MARINE ALGÆ
SEAWEED
When descends on the Atlantic
The gigantic
Storm-wind of the equinox,
Landward in his wrath he scourges
The toiling surges,
Laden with seaweed from the rocks;
From Bermuda's reefs; from edges
Of sunken ledges
In some far-off, bright Azore;
From Bahama and the dashing,
Silver-flashing
Surges of San Salvador;
* * * * *
Ever drifting, drifting, drifting
On the shifting
Currents of the restless main;
Till in sheltered coves, and reaches
Of sandy beaches,
All have found repose again.
LONGFELLOW.
I
BLUE-GREEN SEAWEEDS (CYANOPHYCEÆ)
GRASS-GREEN SEAWEEDS (CHLOROPHYCEÆ)
TABLE SHOWING THE CLASSIFICATION OF THE BLUE-GREEN SEAWEEDS DESCRIBED
IN THIS CHAPTER
Class =ALGÆ=
Subclass =Cyanophyceæ= (/Blue-Green Seaweeds/)
Order =NOSTOCACEÆ=
Genera Species
^Spirulina^
^Oscillaria^
^Calothrix^
^Lyngbya^ ^L. majuscula^
^L. ferruginea^
[pg049]
BLUE-GREEN SEAWEEDS
The minute algæ, which form patches of purple color on rocks, slimy
layers or spots on wharves, bluish-green slime on mud, emerald-green
films on decaying algæ, blue-green slime on brackish ditches, and so
on, are various species of the subclass =Cyanophyceæ=. The prevailing
color of these plants is blue-green, but some are purple, brown, or
pink. Some of them are gelatinous in texture and shapeless, others
have more definite forms; but all are too small to classify without
the aid of a powerful glass, and are not of special interest except
to the botanist.
GENERA ^Oscillaria^ and ^Spirulina^
The genus ^Oscillaria^ is so named from an oscillating movement which
these filamentous plants show when viewed under the microscope. They
are very delicate blue-green threads occurring singly, or in loose or
felt-like floating masses, or like slime or scum, on mud or woodwork.
In ^Spirulina^ the filaments are spirally twisted like a corkscrew
and also have a vibrating movement. /Spirulina/ is often found
growing with /Oscillaria/, and forms purple patches on wharves.
GENUS ^Calothrix^
("/Beautiful hair/")
Filaments one tenth of an inch long, terminating in transparent
hair-like points, occasionally branching. The plant grows in fine
tufts or like a fringe on algæ or in patches on rocks. Sometimes it
forms a spongy layer, again a velvety stratum. The color varies in
different species; it may be bright green, brownish-green, [pg050]
or dark bluish-purple. The genus is very common, and the plants are
often found on the bottoms of boats.
GENUS ^Lyngbya^
(/Named for Hans Christian Lyngbye, a Danish botanist/)
^L. majuscula^, mermaid's-hair. The filaments are curled or
crisped, long, thick, and tenacious, matted together at the base,
and blackish-green. The species grows in tufts on eel-grass and
algæ, and is often found floating free. It is common in summer
everywhere south of Cape Cod and on the Pacific coast.
^L. ferruginea^ or ^æstuarii^. In this species the filaments are
thin, soft, and without stability (flaccid), so that they lie flat
like a thin stratum. They are verdigris-green in color, and are
found in brackish pools and ditches and on muddy shores near the
sea. [pg051]
TABLE SHOWING THE CLASSIFICATION OF THE GRASS-GREEN SEAWEEDS
DESCRIBED IN THIS CHAPTER
Class =ALGÆ=
Subclass =Chlorophyceæ= (/Grass-Green Seaweeds/)
Order Genus Species
=CONFERVACEÆ= ^Ulothrix^
^Chætomorpha^ ^C. melagonium^
^C. ærea^
^C. linum^
^Cladophora^ ^C. arcta^
^C. rupestris^
^C. gracilis^
=ULVACEÆ= ^Ulva^ ^U. lactuca^
^U. latissima^
^Enteromorpha^ ^E. clathrata^
^E. compressa^
^E. intestinalis^
^E. lanceolata^
^Monostroma^
Group =Siphoneæ=
=VALONIACEÆ= ^Chamædoris^ ^C. annulata^
^Anadyomene^ ^A. flabellata^
=DASYCLADACEÆ= ^Acetabularia^ ^A. crenulata^
^Dasycladus^ ^D. occidentalis^
^Cymopolia^ ^C. barbata^
=UDOTEACEÆ= ^Penicillus^ ^P. dumentosus^
^P. capitatus^
^P. Ph[oe]nix^
^Udotea^ ^U. flabellata^
^U. conglutinata^
^Halimeda^ ^H. tuna^
^H. tridens^
^H. opuntia^
=CODIACEÆ= ^Bryopsis^ ^B. plumosa^
^Codium^ ^C. tomentosum^
=CAULERPACEÆ= ^Caulerpa^ ^C. prolifera^
^C. Mexicana^
^C. plumosa^
^C. Wurdemanii^
[pg052]
GRASS-GREEN SEAWEEDS
"There can hardly be a more fascinating group of plants than this,
whether to the strictly scientific botanist or to the more catholic
lover of nature. The green algæ are among the most widely diffused
of plant forms. They grow practically in every place where enough
moisture, together with light and air, is to be had. Between
tide-marks on almost every coast, floating on the surface of the deep
sea, covering damp earth, walls, palings, and tree-trunks, sticking
to the surface of leaves in the moist atmosphere of tropical forests
and jungles, and inhabiting almost every river, brook, pond, ditch,
or casual pool of rain-water in all quarters of the globe, are
members of this ubiquitous group to be found."[3]
[Footnote 3: Kerner.]
The grass-green seaweeds are more simple in structure, and therefore
are lower in order, than the red or brown algæ. They are among the
lowest of all plants, many of them being minute single cells. They
abound in fresh as well as in salt water, and in this respect differ
from the other groups, the red and the brown algæ being almost
exclusively marine plants.
As one approaches the shore, the attention is often attracted by the
green mantle which covers everything overflowed by the tides. This
consists largely of the confervoid algæ, which are very abundant and
are found almost everywhere. They are dense tufts of fine thread-like
plants, often matted at the base; sometimes they are sponge-like,
floating masses.
The =Ulvaceæ=, the plants next higher in order, are the first which
assume ribbon- and leaf-like expansions, and usually first engage the
attention of the collector. [pg053]
In the green algæ are found the extreme forms of one-celled plants.
In ^Pleurococcus^ the cell is microscopic in size. In the =Siphoneæ=
the plant still consists of a single cell, but it attains large
dimensions and develops into forms resembling, in outward appearance,
leaf, stem, and root (see /Caulerpa/).
Other plants consist of single rows of cells, called filaments
(=Confervaceæ=), or of cells arranged in layers or flat surfaces,
called membranes (=Ulvaceæ=).
ORDER =CONFERVACEÆ=
The silkweeds. This order is characterized by cylindrical cells
strung end to end, forming threads or filaments, branched and
unbranched. The plants inhabit both fresh and salt water, and are
very abundant and widely distributed. They grow in dense tufts, often
matted at the base.
GENUS ^Ulothrix^
A yellow-green, unbranched, decumbent, soft, hair-like fleece on the
surface of rocks, extending indefinitely. This genus differs from
/Chætomorpha/ in the character of its filaments, which are soft and
gelatinous in ^Ulothrix^, but bristle-like and wiry in /Chætomorpha/.
GENUS ^Chætomorpha^
The frond is filiform; the filaments are coarse, rigid, and
unbranched. In some species the filaments grow straight and in
tufts from a definite base; in others they are twisted together
and are prostrate. Often they are found floating in masses. In ^C.
tortuosa^ the filaments are as fine as human hair, but rigid, and so
closely interwoven as to resemble a layer of wool on the rocks. The
cell-divisions give a striped appearance to the filaments when dry.
^C. melagonium.^ This species is dark green, with filaments erect,
coarse as a double bristle, and wiry; five to twelve inches long.
It is found in rock pools from Boston northward. It does not adhere
to paper in drying, and loses its color if immersed in fresh water.
(Plate III.)
^C. ærea.^ Yellowish-green, with filaments erect and less rigid
than [pg054] in /C. melagonium/, which it otherwise resembles;
tufts three to twelve inches long; cell-divisions very marked. This
species is found in rock pools from Cape Cod to New York Bay.
^C. linum.^ Bright green; filaments coarse, rigid, twisted
together, and prostrate. It is found floating in masses and forming
strata on rocks and gravel from New York northward. It is thought
by some that this, as well as ^C. picquotiana^, which it closely
resembles, is not a true species, but consists of the mature plants
of the species /C. melagonium/ and /C. ærea/, which have become
detached from their holdfasts and have continued to grow. (Plate
III.)
GENUS ^Cladophora^
("/Branch-bearing/")
Frond filiform, branched. There are many species of ^Cladophora^,
which differ from one another in their branching, color, and size.
They abound on rocks at low-water mark, in tide-pools, in muddy
ditches, and on wharves. They are especially characterized by being
so profusely branched as to form tufts or spherical masses, by which
the collector can easily distinguish the genus.
^C. arcta.^ Bright, glossy green; filaments fine, erect, much
branched, two to eight inches long; tufts dense, more or less
entangled, and in bunches, giving a starry effect. The species is
common on rocks near low-water mark from New York northward. The
plants vary slightly in appearance with the season. (Plate III.)
^C. rupestris.^ Dark green; filaments straight, rigid, tufted;
branches crowded; many branchlets flattened against the filaments,
so that the alga somewhat resembles grass; five to ten inches long.
The cell-divisions show plainly. Plants of this species do not
adhere to paper in drying. They are found on rocks at low-water
mark, and are common on the northern New England coast. (Plate III.)
^C. gracilis.^ Bright yellow-green; filaments very fine, loosely
tufted, three to twelve inches long, soft, silky, much branched;
branches rather short, and branchlets more or less curved and
arranged in a comb-like manner. It grows on wharves, in muddy
pools, and on eel-grass. (Plate IV.)
[Illustration: PLATE III. Chætomorpha melagonium. Chætomorpha linum.
Cladophora arcta. Cladophora rupestris.]
[Illustration: PLATE IV. Cladophora gracilis. Ulva lanceolata. Ulva
lactuca, var. rigida. Enteromorpha clathrata.]
ORDER =ULVACEÆ=
The plants of this order are, with few exceptions, formed of celled
surfaces and show the earliest type of an expanded leaf. The cells
form thin membranes, which sometimes are broad surfaces of no
definite shape, sometimes are narrow and ribbon-like, or they may be
simple or branched tubes. When the membrane [pg055] consists of
a single layer of cells it is ^Monostroma^ ("one layer"); when it
consists of a double layer it is ^Ulva^; when the layers separate,
the thallus becomes hollow, and it is then ^Enteromorpha^. These
plants are mostly a brilliant grass-green in color, are silky in
texture, and are attached by a small disk to rocks and stones. They
abound everywhere, and are commonly known as /green laver/.
GENUS ^Ulva^
Frond a thin, silky, flat membrane, sometimes leaf-like, again an
extended surface of no definite shape. These are the largest green
algæ. They are common everywhere.
^U. lactuca^, the sea-lettuce. Frond a flat membrane of various
shapes, sometimes orbicular, again deeply incised, often
ribbon-like; margin always much waved or ruffled. In the variety
^rigida^ the frond is oval in outline, not very large, and quite
firm or rigid. The species is found on rocks exposed to the action
of the waves. (Plate IV.)
^U. latissima.^ Frond a flat, expanded membrane of indefinite
shape, but general outline oval, never ribbon-like; attains a
size of twelve to twenty-four inches; often deeply lobed, very
waved, often perforated with holes; membrane brilliant green,
thin, smooth, glossy. It grows apart or in tufts, and is found
everywhere, in all stages of growth. It is the largest species of
/Ulva/, and is very common on muddy shores.
GENUS ^Enteromorpha^
Fronds tubular, simple or branched, sometimes inflated. The tubes
vary in size in different species and also in the same species, some
being fine like a hair, others large, and flat or inflated. The genus
is widely distributed and very abundant. Species of ^Enteromorpha^
grow on the bottoms of ships, and in nautical language are called
/grass/.
^E. clathrata.^ Fronds thread-like, tubular, branched, and branches
beset with numerous fine branchlets; densely tufted, soft. Common
everywhere. (Plate IV.)
^E. compressa.^ Fronds long, slender, branched, tufted; branches
simple, compressed, extending from main central branch, obtuse
at ends, but attenuated at base. The species is very abundant
everywhere, and is a useful plant for the aquarium. (Plate V.)
^E. intestinalis.^ Single, long, inflated tubes or sacs, obtuse at
the apex, very attenuated at the base; fronds often crimped and
twisted, resembling an intestine, whence the name. (Plate V.)
[pg056]
^E. lanceolata.^ Formerly called /Ulva Linza/. Frond narrow,
ribbon-like, six to twelve inches long, one inch to two inches
wide; blunt or pointed at apex, tapering at base; attached by a
disk; edges much ruffled; bright green, soft, thin.
GENUS ^Monostroma^
This genus resembles /Ulva/, but is more delicate since it
has but one layer of cells, as its name implies. The frond is
usually sac-like at first, then breaks apart, leaving a thin,
semi-transparent membrane of no definite shape.
GROUP =SIPHONEÆ=
The distinct and peculiar character of this group is that in each
individual the whole plant consists of but one cell. There are many
genera, some of which are plants of elaborate form and considerable
size, but always the one cell expands and branches without dividing
the elongated cavity with septa, or plates of division. In ^Caulerpa^
the stability of the plant is secured by numerous fibrils which
emanate from the interior of the cell, forming a spongy network of
interlacing filaments. In other orders the branches gain support from
incrustation, from interlacing, and from cohering on the edges.
ORDER =VALONIACEÆ=
The algæ of this order are found only in tropical or subtropical
waters. Their holdfasts resemble fibrous roots and penetrate the sand
or coral on which they grow.
GENUS ^Chamædoris^
^C. annulata.^ When young this alga consists of an annulated tube
formed of a single cell. The annular constrictions occur at short
intervals, giving it the appearance of being jointed. It grows to
the height of two to three inches, when it ceases to lengthen and
produces a dense mass of filaments, forming a head or spherical
tuft one inch or more in diameter. It is bright grass-green in
color, rather rigid and tough, and when mature is thinly coated
with carbonate of lime. The holdfast is a tuft of fibers. The
species is found at Key West and is a native of the West Indies.
[Illustration: PLATE V. Enteromorpha compressa. Enteromorpha
intestinalis. Enteromorpha intestinalis. Anadyomene flabellata.]
[Illustration: PLATE VI. Acetabularia crenulata. Dasycladus
occidentalis. Penicillus dumentosus. Udotea conglutinata.]
GENUS ^Anadyomene^
^A. flabellata.^ Frond composed entirely of branching filaments,
which unite and form an undulating, rigid membranaceous surface,
which seems like a network of veins. The species grows in bunches
on short stems in the fissures of tidal rocks, and at first view
resembles young /Ulva/. It is a very curious and beautiful alga,
and should be examined with a glass. It is one inch to four inches
in diameter when full-grown. (Plate V.)
ORDER =DASYCLADACEÆ=
This order also inhabits only tropical or subtropical seas. It is
placed in this group, although only the main axis is unicellular.
The one-celled axis is surmounted or encircled by whorls of minute
filaments or branchlets (/ramuli/), which protrude through small
holes and are either persistent or deciduous. In the latter case the
fallen filaments leave disk-like scars on the stem.
GENUS ^Acetabularia^
^A. crenulata.^ This little alga resembles a mushroom of the
/Agaricus/ variety or gilled species, and so is easily identified.
It is thinly incrusted with lime and is found on rocks and coral,
within tide-marks, on the Florida reefs. When full-grown the stipe
is two to three inches long and the cap one half of an inch in
diameter. (Plate VI.)
GENUS ^Dasycladus^
Fronds destitute of calcareous matter, soft, cylindrical or
club-shaped; single unicellular axis, beset with fine filaments or
ramuli.
^D. occidentalis.^ Frond club-shaped, one to two inches high, one
half of an inch or less in diameter; covered with whorls of fine
filaments, making the fronds almost spongy; substance soft but
tough; dark green. These plants have been compared to foxes' tails.
They grow in bunches on rocks between tide-marks. (Plate VI.)
GENUS ^Cymopolia^
^C. barbata.^ Frond branched, dividing regularly in pairs; thickly
incrusted with lime. Annular constrictions at short intervals give
the branches the appearance of strings of beads. Each section
is covered with pores or scars of fallen ramuli. The branches
terminate in tufts of fine filaments. [pg058]
ORDER =UDOTEACEÆ=
GENUS ^Penicillus^
The merman's shaving-brush, characteristic of coral reefs.
^P. dumentosus.^ Holdfast much branched, like a fibrous root, and
penetrating deep into the coral or sand; stem short, thick, more
or less flattened, sometimes hollow, covered with velvety scurf;
top covered with loosely spreading tuft of soft filaments three to
six inches long, which branch repeatedly in pairs (dichotomous);
color deep green. When old, these plants are incrusted with a thin,
porous layer of carbonate of lime. (Plate VI.)
^P. capitatus.^ Holdfast a dense mass of fibers two or more inches
long; stipe one to five inches long, one fourth to one third of an
inch in diameter, usually cylindrical, sometimes wider at top than
at base, sometimes flattened; thickly incrusted with lime, which is
smooth and often polished; top a dense, spherical mass of filaments
one to two inches in diameter; filaments branching dichotomously,
and rigid from incrustation of lime.
^P. Ph[oe]nix.^ Stipe cylindrical, one to three inches long,
one fourth of an inch in diameter, thickly incrusted with lime,
smooth; capitulum or head ovoid, and composed of filaments which
are incrusted with lime and coherent, forming many distinct, flat,
wedge-shaped, level-topped, spreading laminæ. This species is found
at Key West.
GENUS ^Udotea^
^U. flabellata.^ Short, flattened stem, expanding into a broad,
fan-shaped, smooth frond, concentrically zoned; margin wavy;
thickly incrusted with lime. Abundant at Key West.
^U. conglutinata.^ Deeply descending root; stem expanding into
fan-shaped frond; entire, lobed, or irregularly torn; slightly
incrusted with lime. The frond is composed of longitudinally
parallel, adherent filaments, which are visible, giving a striated,
rough surface. (Plate VI.)
GENUS ^Halimeda^
This genus resembles the corallines externally, and is abundant on
coral reefs. It appears as if formed of separate parts, resembling
a series of heart- or kidney-shaped segments strung together. The
plants are more or less incrusted with lime. The branching holdfast
grasps particles of sand, and with them forms a solid ball.
^H. tuna.^ Articulations roundish or half kidney-shaped, one half
to three quarters of an inch broad; frond flat, smooth, and thinner
than most species; bright green; somewhat flexible. (Plate VII.)
[Illustration: PLATE VII. Halimeda tuna. Halimeda tridens. Bryopsis
plumosa. Codium tomentosum.]
[Illustration: PLATE VIII. Caulerpa Mexicana. Caulerpa Wurdemanii.
Caulerpa plumaris. Caulerpa paspaloides.]
^H. tridens.^ Fronds solitary, erect; base composed of
confluent articulations; above divided into numerous branches
of articulations, which are all flat, and in one plane giving a
fan-shaped outline; middle joints wedge-shaped; upper ones divided
into three lobes, frequently bearing articulations at the summit of
each lobe; thinly incrusted with lime; color bright green. (Plate
VII.)
^H. opuntia.^ Articulations kidney-shaped, flat, rather thin;
margins scalloped; irregularly branched and spreading; dense tufts.
ORDER =CODIACEÆ=
GENUS ^Bryopsis^
("/Moss-like/")
There are said to be about twenty species of this genus. They are
distinguished by the manner of branching, but are not very definitely
marked. All are erect, one-celled, branching stalks, and are
feather-like in appearance.
^B. plumosa.^ Fronds branched twice or more; branchlets or pinnules
tapering as they rise on the stalk, giving a triangular outline;
stalk naked below; plants a vivid dark green in color, two to six
inches long, growing in tufts on wharves and stones at low-water
mark and in tide-pools. It is common along the whole Atlantic and
Pacific coasts. It is well to use salt water for mounting this
alga, since the green coloring-matter or granular endochrome with
which it is filled easily escapes. (Plate VII.)
GENUS ^Codium^
^C. tomentosum.^ This is called the commonest seaweed in the world.
It is abundant in every latitude, yet it does not appear on the
eastern coast of North America. It is found on the gulf coast of
Florida and is plentiful on the Pacific coast. The fronds are often
a foot long, composed of closely packed, club-shaped branches
dividing in a forking manner, and densely covered with fine
filaments which give them a soft, sponge-like texture. (Plate VII.)
ORDER =CAULERPACEÆ=
GENUS ^Caulerpa^
(/From two Greek words meaning "stem" and "creep"/)
/Caulerpa/ is the only genus of its order, but it contains about a
hundred species, many of which resemble mosses, ferns, or cacti. Each
plant is composed of a single cell, however much it may be [pg060]
ramified. The frond consists of a prostrate stem, from the lower side
of which root-like fibers or holdfasts descend into the hard sand or
coral, and from the upper side leaf- and branch-like secondary fronds
arise. These plants grow luxuriantly in tropical waters, extending
over large surfaces, and are the chief food of turtles. (Plate VIII.)
^C. prolifera.^ Frond or lamina flat and leaf-like, two to four
inches long, one half to three quarters of an inch wide, either
simple or once forked; margin entire. Similar laminæ spring from
the surface or from the edge or base of the different leaf-like
portions. Laminæ rise from the upper side of the creeping, rooting
stem. Its substance is somewhat horny and translucent.
^C. Mexicana.^ Prostrate, creeping stem, with rootlets or holdfasts
below, and leaf-like fronds above; fronds simple or with one or
two branches deeply cut in narrow lobes nearly to the center. The
species abounds at Key West. (Plate VIII.)
II
OLIVE-GREEN AND BROWN SEAWEEDS (PHÆOPHYCEÆ)
TABLE SHOWING THE CLASSIFICATION OF THE OLIVE-GREEN AND BROWN
SEAWEEDS DESCRIBED IN THIS CHAPTER
Class =ALGÆ=
Subclass =Phæophyceæ= (/Olive-Green and Brown Seaweeds/)
Orders Genera Species
=ECTOCARPACEÆ= ^Ectocarpus^ ^E. littoralis^
^E. siliculosus^
^E. viridis^
^E. tomentosus^
=SPHACELARIACEÆ= ^Sphacelaria^ ^S. cirrhosa^
^S. radicans^
^Cladostephus^ ^C. verticillatus^
=RALFSIACEÆ= ^Ralfsia^
=ENC[OE]LIACEÆ= ^Punctaria^ ^P. latifolia^
^P. tenuissima^
^P. plantaginea^
^Asperococcus^ ^A. echinatus^
^Phyllitis^ ^P. fascia^
=DESMARESTIACEÆ= ^Desmarestia^ ^D. viridis^
^D. aculeata^
^D. ligulata^
^Arthrocladia^ ^A. villosa^
=DICTYOSIPHONACEÆ= ^Dictyosiphon^ ^D. f[oe]niculaceus^
=ELACHISTACEÆ= ^Elachista^
=CHORDARIACEÆ= ^Chordaria^ ^C. flagelliformis^
^Mesogl[oe]a^ ^M. virescens^
^M. divaricata^
^Leathesia^
^Myrionema^
=LAMINARIACEÆ= ^Chorda^ ^C. filum^
^Alaria^ ^A. esculenta^
^Agarum^ ^A. Turneri^
^Laminaria^ ^L. longicruris^
^L. saccharina^
^L. digitata^
^Macrocystis^
^Nereocystis^
^Lessonia^
^Thalassiophyllum^
=DICTYOTACEÆ= ^Dictyota^ ^D. fasciola^
^D. dichotoma^
^Zonaria^ ^Z. lobata^
^Taonia^ ^T. atomaria^
^Padina^ ^P. pavonia^
^Haliseris^ ^H. polypodioides^
=CUTLERIACEÆ= ^Cutleria^ ^C. multifida^
=FUCACEÆ= ^Himanthalia^ ^H. lorea^
^Fucus^ ^F. vesiculosus^
^F. serratus^
^F. furcatus^
^F. ceranoides^
^Ascophyllum^ ^A. nodosum^
^Phyllospora^ ^P. Menziesii^
^Cystoseira^ ^C. expansa^
^Halidrys^ ^H. osmunda^
^Sargassum^ ^S. vulgare^
^S. Montagnei^
^S. bacciferum^
[pg064]
OLIVE-GREEN AND BROWN SEAWEEDS
This subclass contains some of the most remarkable of the seaweeds.
It is especially notable for the diversity of its plant forms, which
range from filaments to plants which appear to have stems and leaves
(/Sargassum/). The species vary in size from very small fronds to
those of immense size (the /Laminariaceæ/). It includes /Fucus/
(the rockweeds), a very conspicuous genus, which furnishes fully
three fourths of the vegetable covering of the tidal rocks in the
localities in which it grows.
ORDER =ECTOCARPACEÆ=
This order comprises many species of branched, filamentous plants,
some of which are of hair-like fineness and form beautiful feathery
tufts of brownish or olive-green color. They resemble, except in
their tawny color, the green alga /Cladophora/.
The name is derived from Greek words meaning "outside" and "fruit,"
the spores of the plants being borne on the branches.
The species are determined by the arrangement of the spores,
according as they are in the pod-like branches, in groups, or in
cases on stalks. Since these differences are not perceptible to the
naked eye, it is impracticable to describe many species, or for the
amateur collector to try to separate them.
GENUS ^Ectocarpus^
^E. littoralis.^ Filaments fine, in dense tufts, interwoven, six to
twelve inches long; pod linear in the substance of the branches;
color olive-green. This is the most common species of /Ectocarpus/,
and grows abundantly everywhere, appearing like large, fine,
dull-green plumes. (Plate IX.) [pg065]
^E. siliculosus.^ Tufts loosely entangled at the base, free and
feathery above, of indefinite length; spores in pod-like forms at
the ends of the branches. Common on the larger algæ and on wharves.
^E. viridis.^ Tufts a little more loose and expanding than in /E.
siliculosus/; spores in pods at the base of the branches. (Plate
IX.)
^E. tomentosus.^ Fine filaments, densely interwoven into rope-like,
spongy masses, two to four inches long; yellowish-brown; pods on
stalks. Found in summer growing on /Fucus/.
ORDER =SPHACELARIACEÆ=
GENUS ^Sphacelaria^
^S. cirrhosa.^ Olive-brown; branched, feathery filaments, one
half of an inch to two inches long. Each branch ends with an
oblong, swollen cell containing a dark granular mass which gives
it a withered appearance. These cells can be seen with a strong
pocket-lens. It forms dense, globe-like tufts on /Fucus/.
^S. radicans.^ Filaments one half of an inch to one inch high;
branches few and hairy. It forms a dense, grass-like covering, of
indefinite extent, on the under side of muddy rocks. Found on the
New England coast.
GENUS ^Cladostephus^
^C. verticillatus.^ Fronds bristle-like, dividing regularly;
covered with whorls of branchlets set close to the stems, each
whorl overlapping the previous one, giving the plant a spongy
appearance. (Plate IX.)
ORDER =RALFSIACEÆ=
GENUS ^Ralfsia^
The species of this genus are brown, leathery, crustaceous expansions
of indefinite form, one inch to six inches in diameter, resembling
lichens. They appear on rocks in shallow, exposed pools.
ORDER =ENC[OE]LIACEÆ=
GENUS ^Punctaria^
Dotted-weeds. Fronds pale olive-green, membranaceous, leaf-like, with
short stem; covered with spores which appear like dots.
^P. latifolia.^ Frond pale green, four to twelve inches long, one
inch to five inches wide, leaf-like, and tapering suddenly to a
short stalk; much [pg066] waved on margin; substance soft and
thin; dotted with spores. In the young plants fine hairs emerge
from the dots, but disappear later, and the fronds become darker
and more rigid. Found in summer on rocks and on other algæ on the
Long Island and New England coasts.
^P. tenuissima.^ Fronds smaller and more slender than in /P.
latifolia/; thin and delicate. Found on eel-grass and /Chorda
filum/.
^P. plantaginea.^ Fronds dark brown, leathery, leaf-like, blunt or
wedge-shaped on top; dense clusters of hairs on the dots; six to
twelve inches long, one inch to one and a half inches wide.
GENUS ^Asperococcus^
This genus differs from /Punctaria/ in having a tubular instead of a
flat frond. (Plate IX.)
^A. echinatus.^ Resembles /Enteromorpha/ in being tubular;
compressed or inflated; obtuse at the apex; attenuated at the
base. It differs from /Enteromorpha/ in being olive in color, and
in being covered with small oblong dots of darker shade. When the
plant is young the dots are hairy. It grows in clusters, two to
eighteen inches long, one half of an inch to one inch wide. Common
along the New England coast.
GENUS ^Phyllitis^
^P. fascia.^ Fronds light olive-green, leaf-like, three to six
inches long, one fourth to one half of an inch wide; margin entire,
slightly waved; contracted at base to short stalk; attached
by disk. This species grows in bunches on rocks and stones at
low-water mark, and is very common everywhere. (Plate X.)
ORDER =DESMARESTIACEÆ=
(/Named for M. Desmarest, a French naturalist/)
GENUS ^Desmarestia^
^D. viridis.^ Filaments cylindrical, about as thick as a bristle;
branches opposite, in pairs, at intervals on the main stem. The
branches branch again and continue to be disposed in the same
manner. All are long and ultimately become very fine. The color is
olive-green, becoming verdigris-green when exposed to the air for
a short time or placed in fresh water. The species grows in deep
tide-pools and below low-water mark, forming fine, feathery plumes,
often a yard long, which give submerged rocks the appearance of a
luxuriant garden. (Plate X.)
[Illustration: PLATE IX. Ectocarpus littoralis. Ectocarpus viridis.
Cladostephus verticillatus. Asperococcus bullosus.]
[Illustration: PLATE X. Phyllitis fascia. Desmarestia viridis.
Desmarestia aculeata. Desmarestia ligulata.]
^D. aculeata^ ("spiny"). Fronds cylindrical at base, flattened
above; branches long and straight, arranged alternately, when young
beset with pencils of fine hairs, often one half of an inch long,
which, later, fall off, leaving alternate spines along the edges of
the flattened branches. It [pg067] grows from one foot to six
feet in length, below low-water mark, and is found washed ashore.
It is an attractive plant in the spring, but is brown and coarse
when old. Common everywhere. (Plate X.)
^D. ligulata.^ Fronds two to six feet long, pinnate, having a
flat main stem one half of an inch or more wide, with opposite
flat branches; leaflets arranged along the edges of the branches,
pointed at each end, and bordered with forward-pointing spines. It
is found washed ashore, in abundance, in California, but is not
found on the Atlantic coast. (Plate X.)
GENUS ^Arthrocladia^
^A. villosa.^ Olive-brown filaments, resembling fine, knotted
threads, each knob having a whorl of delicate filaments. It grows
from six inches to three feet long, in deep water. It is rare, but
is occasionally found on the New England coast.
ORDER =DICTYOSIPHONACEÆ=
GENUS ^Dictyosiphon^
^D. f[oe]niculaceus.^ Fronds filiform, bristle-like, branching
into delicate, hair-like branches; yellowish-brown. It resembles
/Chordaria flagelliformis/, but is much finer. (Plate XI.)
ORDER =ELACHISTACEÆ=
GENUS ^Elachista^
The plants of this genus are small, olive-colored, unbranched,
hair-like filaments, growing in dense, radiating tufts, one half
of an inch in height, on /Fucus/. They are interesting to the
microscopist, but not to the collector.
ORDER =CHORDARIACEÆ=
("/Cord-like/")
GENUS ^Chordaria^
^C. flagelliformis^ ("whip-like"). Firm, leathery, somewhat
elastic, slimy strings, six to twenty-four inches long, and twice
as thick as a bristle; branches mostly undivided, short or long,
irregularly placed on the main axis, and curving inward at the
top of the frond; main axis not extending as far as the branches;
blackish in color; attached by a disk to stones and shells;
solitary or in bunches. It is common along the New England coast.
(Plate XI.) [pg068]
GENUS ^Mesogl[oe]a^
^M. virescens.^ Soft, slimy filaments, with branches and
branchlets; olive-green. (Plate XI.)
^M. divaricata.^ Fronds two to twenty-four inches high; branching
irregularly, and generally without definite main axis; branches
flexuous, solid at first, later hollow; branchlets short and
wide-spreading. Common from Cape Cod southward; abundant in Long
Island Sound. (Plate XI.)
GENUS ^Leathesia^
This singular alga resembles a tuber and cannot be mistaken for any
other plant. Its fronds are gelatinous, fleshy balls, one half of an
inch to two inches in diameter, at first solid, afterward lobed and
hollow. It grows singly or in bunches on algæ and on sand-covered
rocks, and is found in summer on every coast. The common species is
known as /L. difformis/ or /L. tuberiformis/.
GENUS ^Myrionema^
Minute algæ which grow on other plants and which appear like dark
spots, or, at first, like stains, on /Ulva/, /Enteromorpha/, and
small red algæ. These spots, which to the naked eye appear like
decay, show, under the microscope, a jelly-like substance full of
beaded filaments.
ORDER =LAMINARIACEÆ=
The plants of this order have large and coarse fronds (some
attaining an immense size), with stems, branching root-like
holdfasts, and expanded leaf-like laminæ. They are leather-like, not
articulated, olive-green or brown in color, and sometimes yellow
and semi-transparent. They grow in deep water and are found washed
ashore. Sometimes small plants are found in deep tide-pools at
low-water mark. Some species are perennial. In these instances the
stems only survive, and the laminæ are reproduced annually. The new
growth takes place at the apex of the stem. The old lamina is pushed
off, but is held on the summit of the new growth until the latter has
matured.
[Illustration: PLATE XI. Dictyosiphon f[oe]niculaceus. Chordaria
flagelliformis. Mesogl[oe]a virescens. Mesogl[oe]a divaricata.]
[Illustration: PLATE XII. Chorda filum. Agarum Turneri. Alaria
esculenta. Laminaria saccharina.]
In the genus /Chorda/ the fronds are cylindrical; in /Agarum/
[pg069] the laminæ are perforated; in /Alaria/ there are wing-like
leaflets below the laminæ.
The /Laminariaceæ/ and /Fucaceæ/ are the seaweeds used in making
kelp. For this the algæ are burned, and the ash is then separated
into its different mineral constituents and used for various
manufacturing purposes.
GENUS ^Chorda^
^C. filum.^ Entire frond cylindrical, divided internally by
transverse septa; one fourth to one half of an inch in diameter,
tapering at each end; ordinarily one to twelve feet long, but
sometimes attaining a length of forty feet. When young the frond
is covered with fine, transparent hairs; later it is brown and
leather-like. The growth takes place at the base, just above the
disk-like holdfast, and at the apex it is constantly dying off. The
species is common on Northern shores, at and below low-water mark.
Often it is in masses which seem like meadows of waving grass under
water. Various small algæ and many zoöphytes are to be found on the
fronds. (Plate XII.)
GENUS ^Alaria^
This genus is readily distinguishable by the fact that it has
leaflets below the lamina. It is found north of Cape Cod.
^A. esculenta.^ Stem compressed, four to twelve inches long, one
fourth to one half of an inch wide, and running like a midrib
through the lamina; lamina one to ten feet long, two to ten inches
wide, frequently torn and ragged; margin wavy; leaflets three to
eight inches long and without midrib, growing on both sides of the
stem, below the lamina. The spores are produced in the leaflets in
the autumn. This is an edible alga and is used as food in Scotland
and Ireland, where it is called henware, badderlocks, murlins, and
so on. (Plate XII.)
GENUS ^Agarum^
The sea-colanders.
^A. Turneri.^ Stem two to twelve inches long, round below,
flattened above, and extending like a midrib through the lamina;
lamina one foot to four feet long, with holes over the whole
surface; margin wavy. The perforations in the lamina are produced
by conical hollow papillæ which cover the young frond and which at
length burst, leaving a hole which enlarges as the plant expands.
This species is found from Cape Cod to Greenland.
There are other species, which differ from this one in the size of
the perforations, the shape of the lamina, and the prominence of
the midrib. Harvey describes the plant as an arctic genus growing
ten to twelve feet long. (Plate XII.) [pg070]
GENUS ^Laminaria^
The plants of this genus are all large, varying from one foot to
twelve feet or more in length. They are of wide geographical range,
and are more numerous in species than any others of the order. They
are commonly known as oarweeds, tangle, devil's-aprons, sole-leather,
kelp, sea-furbelows, and so on.
^L. longicruris^ ("long-stalked"). Stem six to twelve feet long,
one to two inches thick, slender and solid at base, hollow and
inflated at the middle, contracted at the top; attached by a
strong, branching, root-like holdfast; color light brown. The
large, single, leaf-like lamina, usually shorter than the stem, is
five to twenty feet long, two to three feet broad, with much waved
and folded margin, outlined with two rows of depressed spots. The
spores form a band in the center of the blade. Found from Cape Cod
northward and on the Pacific coast.
^L. saccharina^, the sea-tangle. This species differs from /L.
longicruris/ in having a short, solid stem and narrow, ribbon-like
lamina. Stem three inches to four feet long; lamina three to
thirty feet long, six to eighteen inches wide, with central
band of depressed spots; margin much waved; color olive-green,
semi-transparent. It is named from the saccharine matter, called
/mannite/, which it contains. Found on northern shores of the
Atlantic and the Pacific oceans. (Plate XII.)
^L. digitata^ ("fingered"). Stem one to five feet long, thick,
round, and solid; lamina oval at base, leathery, smooth, brown,
deeply cleft into segments of unequal breadth. It is named from the
hand-like form of the lamina. This species is found in Long Island
Sound, but is not common south of Cape Cod. The stem is used by
fishermen for knife-handles. Pieces of it, placed on the blades
while green, contract in drying and become solid. (Plate XIII.)
For the genera ^Macrocystis^, ^Nereocystis^, ^Lessonia^, and
^Thalassiophyllum^, see the Introduction, pages 35, 36.
ORDER =DICTYOTACEÆ=
GENUS ^Dictyota^
^D. fasciola.^ Fronds olive-brown, expanded, membranaceous, erect,
flat; many times forked narrow branches; grows in tufts six to ten
inches long, matted at the base.
^D. dichotoma.^ Same as /D. fasciola/, except that the divisions of
the forked frond are one eighth to one half of an inch wide. Found
in tide-pools in Southern waters. (Plate XIII.)
[Illustration: PLATE XIII. Laminaria digitata. Dictyota dichotoma.
Taonia atomaria. Padina pavonia.]
[Illustration: PLATE XIV. Haliseris polypodioides. Cutleria
multifida. Fucus vesiculosus.]
GENUS ^Zonaria^
^Z. lobata.^ Thallus flat, fan-shaped, but not so rounded as
in /Padina pavonia/, twelve or more inches in height, cleft
irregularly into many [pg071] narrow lobes, the clefts
extending nearly or quite to the base; olive-green, with concentric
zones of darker color; edges thin and bordered with a dark line.
Found in southern California and in tropical and subtropical seas.
GENUS ^Taonia^
^T. atomaria.^ Spreading, fan-shaped frond; clefts irregular and
not extending to the basal stem; spores arranged in dark wavy
lines and spots on the frond, giving it a mottled appearance and
beautiful gradation of color. Found in tropical seas. (Plate XIII.)
GENUS ^Padina^
^P. pavonia^, the peacock's-tail. Frond broadly fan-shaped;
substance between membranaceous and leathery; powdery on the
outer surface; deeply and variously cleft or entire; several
laminæ emanating from a stalk-like base; each lamina fan-shaped;
concentric lines numerous; variegated in zones. This beautiful alga
is always regarded as a prize. It is found on stones at low-water
mark, and is not uncommon south of Charleston, South Carolina, but
is more luxuriant in tropical seas. (Plate XIII.)
GENUS ^Haliseris^
The sea-endive.
^H. polypodioides.^ Fronds flat, forked, notched on lower part;
divisions about one quarter of an inch wide; distinct midrib;
olive-green; grows in tufts. It is found in North and South
Carolina, and is abundant on the Florida Keys. (Plate XIV.)
ORDER =CUTLERIACEÆ=
GENUS ^Cutleria^
^C. multifida.^ Frond erect, flat; branches in a forking manner;
ultimate branches fine and short, and with branchlets on the tips.
This species resembles /Taonia/. It is found in Southern waters.
(Plate XIV.)
ORDER =FUCACEÆ=
GENUS ^Himanthalia^
^H. lorea^, the sea-thong. A cup-shaped base, from the center of
which arises a flat, strap-like frond one fourth to one half of an
inch wide and two to twenty feet long, branching dichotomously (or
by forking), and dotted with pits, or conceptacles, in which the
spores are formed. Found in the extreme North. [pg072]
GENUS ^Fucus^
The rockweeds. The plants of this genus grow in thick bunches, and
are found in great abundance between tide-marks. The plants are
attached by sucker-like disks to the rocks, from which they hang like
fringe when the tide recedes; when it rises they float and sway in
the water in beautiful bouquet-like forms. In color they are brown or
olive-green, in texture thick and leathery, but they sometimes expand
into thin membranes. They are many times forked in the same plane,
which produces a flat thallus. They often have a distinct midrib. The
air-vessels, whose function it is to float the plant, are disposed
along the midrib, usually in pairs.
The species are named according to the divisions of the frond,
and the disposition, or presence, of the air-bladders and the
/conceptacles/, or spore-chambers.
The conceptacles congregate in particular portions of the frond and
give its surface a roughness which is very perceptible; such portions
are then known as the /receptacles/. In /Fucus/ this usually occurs
on the bulbous extremities of the branches. Under the microscope a
section of one of these little pointed spots shows a spherical cavity
filled with a beautiful arrangement of /paraphyses/, or threads,
some of which hold spores, while others protrude through a small
opening in the outer membrane. Conceptacles are peculiar to the
order =Fucaceæ=. In them spore-production is carried on in a manner
as complicated as is the formation of seeds in flowering plants.
Although rockweeds are such a conspicuous feature of sea-shore
vegetation, two species only, /Fucus vesiculosus/ and /Ascophyllum
nodosum/ (formerly called /Fucus nodosus/), are common on the
Atlantic coast, and these do not occur south of New York, owing to
the fact that a long stretch of sand-beach extends beyond that point.
^F. vesiculosus.^ Midrib distinct through all the forked branches;
margin entire, often wavy; air-vessels spherical or oblong, usually
in pairs along the midrib; receptacles on terminal branches, which
are swollen and filled with gelatinous matter, heart-shaped or
forked, in oblong or pointed divisions; frond tough and leathery,
often two feet long. (Plate XIV.)
[Illustration: PLATE XV. Fucus serratus. Fucus ceranoides.
Ascophyllum nodosum.]
[Illustration: PLATE XVI. Phyllospora Menziesii. Halidrys osmunda.
Sargassum vulgare.]
^F. serratus.^ Frond distinctly toothed or serrated along the
margin; midrib conspicuous through the main axis and forked
branchings; no air-vessels. This species is rare on the Atlantic
coast. (Plate XV.)
^F. furcatus.^ Frond narrow, tough, without air-vessels; regular
forked branching; midrib distinct below, inconspicuous above;
receptacles long, narrow, not inflated. Found from Boston northward.
^F. ceranoides.^ Frond flat, rather membranaceous, or less leathery
than in the preceding species; repeatedly forked; midrib not
running through every division; no air-vessels. (Plate XV.)
GENUS ^Ascophyllum^
^A. nodosum.^ This species, formerly called /Fucus nodosus/, is
next to /Fucus vesiculosus/ the most common rockweed. Frond one to
five feet long, dark brown, strap-like, leathery; width of main
stems one fourth of an inch or more, and uniform throughout; large,
single, oblong air-vessels distend the frond at intervals. Branches
of various length emerge from the sides of the main stem. Ovoid or
ellipsoidal branchlets or receptacles, single or in groups, occur
at intervals along the sides of both stem and branches. These fall
off after a time and are found in quantities in tide-pools. (Plate
XV.)
GENUS ^Phyllospora^
^P. Menziesii.^ Branching holdfast; short stem which immediately
divides into strap-like branches; branches edged with leaves
varying in length, rounded at top, narrow, stalked at base; leaves
placed at intervals, or crowded together, and interspersed with
air-vessels which are often tipped with leaflets; stems expand at
summit into leaf-like laminæ and are edged with leaflets at the
base; plant often one hundred and twenty feet or more in length;
tough and leathery in substance. Very common on the California
coast. (Plate XVI.)
GENUS ^Cystoseira^
^C. expansa.^ Frond long, slender, repeatedly branched; air-vessels
ellipsoidal and "chained" together in the lower half of the
branches. The plant grows in deep water, ad shows iridescent colors
when seen through the water. It is found on the California coast.
GENUS ^Halidrys^
^H. osmunda^, the sea-oak. Frond flat, alternately toothed
or indented below; branched apex, bearing air-vessels like
long-stalked pods; substance leathery. Found on the coast of
southern California. (Plate XVI.)
GENUS ^Sargassum^
^Sargassum^ is distinguished by its differentiation into stem and
leaf, resembling in outward appearance the higher plants. It [pg074]
is a tropical and subtropical genus, and has one hundred and fifty
species. Two of these, /S. vulgare/ and /S. Montagnei/, are found as
far north as Cape Cod. See Introduction, page 34.
^S. vulgare.^ Stems cylindrical; branches alternate; leaves long,
narrow, toothed, with short stalk and midrib; minute dark spots
on its surface; air-vessels small balls resembling berries set on
stalks and usually tipped with a long point; receptacles small,
twig-like forms in the axils of the leaves; color olive-brown;
plant one foot to three or more feet long. Common in Long Island
Sound. (Plate XVI.)
^S. Montagnei.^ This species resembles /S. vulgare/, but is more
slender in all its parts, and the receptacles are more elongated.
From south of Cape Cod.
^S. bacciferum.^ Particular interest attaches to this species from
the fact that it is the one which forms the floating vegetation
of the Sargasso Sea. It grows attached on the Florida Keys and in
the West Indies. Specimens are sometimes carried by the currents
northward, and are found washed ashore. It differs from /S.
vulgare/ in the leaves, which are thicker, more attenuated, and
sharply toothed, and in having a greater number of air-vessels.
A branch of this species brought from the Sargasso Sea had
air-vessels so numerous and closely set that it resembled a bunch
of small grapes.
III
RED SEAWEEDS
(RHODOPHYCEÆ OR FLORIDEÆ)
TABLE SHOWING THE CLASSIFICATION OF THE RED SEAWEEDS DESCRIBED IN
THIS CHAPTER
Class =ALGÆ=
Subclass =Rhodophyceæ or Florideæ= (/Red Seaweeds/)
Order =NEMALIONACEÆ=
Suborders Genera Species
~HELMINTHOCLADIEÆ~ ^Nemalion^ ^N. multifidum^
^Liagora^
~CHÆTANGIEÆ~ ^Scinaia^ ^S. furcellata^
~GELIDIEÆ~ ^Gelidium^ ^G. corneum^
Order =GIGARTINACEÆ=
^Chondrus^ ^C. crispus^
^Gigartina^ ^G. mamillosa^
^G. radula^
^G. spinosa^
^G. microphylla^
^Phyllophora^ ^P. membranifolia^
^P. Brodiæi^
^Sternogramme^ ^S. interrupta^
^Gymnogongrus^ ^G. Norvegicus^
^Ahnfeldtia^ ^A. plicata^
^Callophyllis^ ^C. variegata^
^C. laciniata^
^Iridæa^
Suborders Genera Species
~RHODOPHYLLIDEÆ~ ^Cystoclonium^ ^C. purpurascens^
^C. cirrhosa^
^Euthora^ ^E. cristata^
^Rhodophyllis^ ^R. veprecula^
^Rhabdonia^ ^R. tenera^
^R. Coulteri^
^Eucheuma^ ^E. isiforme^
Order =RHODYMENIACEÆ=
~SPHÆROCOCCEÆ~ ^Gracilaria^ ^G. multipartita^
^Hypnea^ ^H. musciformis^
~RHODYMENIEÆ~ ^Rhodymenia^ ^R. palmata^
^Lomentaria^ ^L. Baileyana^
^Champia^ ^C. parvula^
^Chylocladia^ ^C. articulata^
^Plocamium^ ^P. coccineum^
~DELESSERIEÆ~ ^Nitophyllum^ ^N. laceratum^
^N. Ruprechteanum^
^N. punctatum^
^Grinnellia^ ^G. Americana^
^Delesseria^ ^D. sinuosa^
^D. alata^
^D. Leprieurii^
~RHODOMELEÆ~ ^Polysiphonia^ ^P. fastigiata^
^P. nigrescens^
^P. parasitica^
^P. dendroidea^
^P. Baileyi^
^P. Harveyi^
^P. Olneyi^
^P. fibrillosa^
^P. violacea^
^P. urceolata^
Var. ^formosa^
^P. variegata^
^P. Woodii^
^Laurencia^ ^L. pinnatifida^
^Dasya^ ^D. elegans^
^D. plumosa^
^Bostrychia^ ^B. rivularis^
^Rhodomela^ ^R. subfusca^
^R. Rochei^
^R. larix^
^R. floccosa^
^Chondria^ ^C. dasyphylla^
^C. tenuissima^
^C. striolata^
Suborders Genera Species
~CERAMIEÆ~ ^Callithamnion^ ^C. americanum^
^C. Pylaisæi^
^C. Baileyi^
^C. seirospermum^
^C. byssoideum^
^C. floccosum^
^Griffithsia^ ^G. Bornetiana^
^Ptilota^ ^P. serrata^
^P. elegans^
^P. densa^
^P. hypnoides^
^Spyridia^ ^S. filamentosa^
^Ceramium^ ^C. rubrum^
Var. ^proliferum^
Var. ^secundatum^
^C. strictum^
^C. diaphanum^
^C. fastigiatum^
^C. tenuissimum^
Var. ^patentissimum^
^Microcladia^ ^M. Coulteri^
^M. borealis^
Order =CRYPTONEMIACEÆ=
~GLOIOSIPHONIEÆ~ ^Gloiosiphonia^ ^G. capillaris^
~GRATELOUPIEÆ~ ^Halymenia^ ^H. ligulata^
^Grateloupia^ ^G. Cutleria^
^Prionitis^ ^P. lanceolata^
^P. Andersonii^
~DUMONTIEÆ~ ^Pikea^ ^P. Californica^
^Halosaccion^ ^H. ramentaceum^
~RHIZOPHYLLIDEÆ~ ^Polyides^ ^P. rotundus^
~SQUAMARIEÆ~ ^Peyssonnelia^ ^P. Dubyi^
^Petrocelis^ ^P. cruenta^
^Hildenbrandtia^ ^H. rosea^
~CORALLINEÆ~ ^Corallina^ ^C. officinalis^
^Melobesia^
Order =BANGIACEÆ=
^Bangia^ ^B. fusco-purpurea^
^Porphyra^ ^P. vulgaris^
^P. laciniata^
[pg079]
RED SEAWEEDS
In =Rhodophyceæ=, known also as =Florideæ= and =Rhodospermeæ=,
algæ attain their highest development. This is marked by the mode
of reproduction, which, more nearly than in the other subclasses,
resembles that of flowering plants. The fronds, however, are not as
large and do not as closely resemble stem and leaf as do some species
of the brown algæ.
The species of this subclass are very numerous, and the variety in
their fronds, their delicate texture, and their colors, which vary
from pink to purple, make them the most attractive of the seaweeds.
They grow mostly in deep water, but are often found washed ashore,
and many grow just below low-water mark and on the shady side of
tide-pools.
In the simplest species the frond consists of branched cell-rows.
In some of these the filaments are so fine that a pocket-lens is
required to determine the differences in branching and fully to
appreciate the beauty of the plant (/Callithamnion/). Some have a
cell-surface. In /Delesseria/ the membrane assumes the outline of a
foliage-leaf. /Dasya/, which is an abundant variety, is especially
beautiful in its feather-like appearance. The corallines are singular
in that they are incrusted with lime and resemble corals.
ORDER =NEMALIONACEÆ=
SUBORDER ~HELMINTHOCLADIEÆ~
GENUS ^Nemalion^
The threadweeds.
^N. multifidum.^ Frond six to twelve inches long, cylindrical,
solid, cord-like, elastic, tough, shiny, very gelatinous; branches
repeatedly in [pg080] a wide-forking manner; sometimes a branch
will divide into several parts at the same point; color dark brown
or purple. It is found, in summer only, from Long Island Sound
northward, growing on smooth rocks which are exposed to the action
of the waves.
GENUS ^Liagora^
Fronds filamentous; branching regularly in a forking manner to the
very top, forming thick bunches; slightly incrusted with lime, yet
somewhat viscid. It is found in Florida and California, and abounds
in tropical waters.
SUBORDER ~CHÆTANGIEÆ~
GENUS ^Scinaia^
^S. furcellata.^ Frond cylindrical, one eighth of an inch in
diameter, tapering at base, sometimes constricted at intervals,
regularly and several times forked, ending in short divisions;
branches of same length, giving a level top; two to four inches
high; lake-red. When pressed the axis is visible, giving the
appearance of a flat frond with a midrib. This species is found
in summer only, washed ashore from Cape Cod southward and on the
California coast. It is not common. (Plate XVII.)
SUBORDER ~GELIDIEÆ~
GENUS ^Gelidium^
^G. corneum.^ Frond flat and horny, one inch to four inches high,
narrow, erect, branched several times in the same plane; ultimate
branchlets club-shaped, or swollen at the tips with masses of
spores; color purple-red. It grows in tufts on mud-covered rocks,
and on algæ at low-water mark. The typical form is found in Florida
and on the Pacific coast. Smaller plants are found all along the
Atlantic shore. It is an extremely variable plant, and is often
difficult to distinguish on this account. (Plate XVII.)
[Illustration: PLATE XVII. Scinaia furcellata. Gelidium corneum.
Gelidium Coulteri. Chondrus crispus.]
ORDER =GIGARTINACEÆ=
GENUS ^Chondrus^
Carrageen or Irish moss.
^C. crispus.^ Frond begins with flattened stem, which divides and
subdivides many times in a broad-forked, fan-like manner; varies
greatly in length and breadth of divisions, also in size and color,
according to conditions of its habitation. In shallow tide-pools
it is pale and [pg081] stunted; but under the shelter of
rocks, in deep water, it grows in dense masses and is a dark
purplish-red or reddish-green. Often it appears iridescent when
seen through the water, with the sun shining on it. It is firm and
leathery in substance. It is an edible alga, and was formerly very
generally used for culinary purposes. At Hingham, Massachusetts,
large quantities are gathered as an article of commerce. It is a
beautiful and very common plant found from New York northward.
(Plate XVII.)
GENUS ^Gigartina^
Of the species of this genus but one is found on the eastern coast;
on the Pacific coast there are several, and they are large and
conspicuous.
[Illustration: PLATE XVIII. Gigartina mamillosa. Gigartina radula.
Gigartina spinosa. Gigartina microphylla.]
^G. mamillosa.^ Frond three to six inches high, one inch to two
inches broad, flat, leathery, gelatinous; forking near the base,
then dividing and subdividing in the same plane; segments more or
less wedge-shaped and with a tendency to roll inward; covered with
numerous small nipple-like protuberances which contain the spores.
These projections distinguish this genus from /Chondrus/, which it
otherwise resembles, and with which it grows. The color is dark
purple. It is found from Boston northward. (Plate XVIII.)
^G. radula.^ Frond flat and thick; rising from a short stem
and widening to several inches; sometimes tapering to the top,
sometimes blunt or divided, sometimes cleft on the sides, but
usually simple; covered with wart-like projections; color dark,
livid red. It is found on the Pacific coast at all seasons, growing
on rocks between tide-marks. Large specimens are one foot to three
feet long and six to ten inches wide. (Plate XVIII.)
^G. spinosa^ ("thorny"). Frond thick, leathery; surface rough and
spiny; form variable, the divisions sometimes emanating from a
broad, flattened base, or again branching from a main axis; all
covered with the protruding processes peculiar to the genus; color
dark red, brown, or purple. It is found on the California coast.
(Plate XVIII.)
^G. microphylla^ ("small-leaved"). Plant rises from short, flat
stem, and rapidly expands into a flat, wide, thin frond which is
simple or divided into two or three segments, each of which tapers
into a long, pointed apex; thickly covered with long, slender
spines, and on its edges bearing small, thin leaflets; color
brownish-red. It is abundant on the California coast. (Plate XVIII.)
GENUS ^Phyllophora^
Leafweed. Fronds cylindrical; branched stalks which expand into
rigid, membranaceous, simple or cleft, wedge-shaped laminæ; laminæ
bear leaflets on their edges or on their surface; spores in masses
form projections on the surface, or are on stalks at the summit;
color dark red. Found washed ashore from New York northward. [pg082]
^P. membranifolia.^ Several stems rise from same disk; branches
expand into wedge-shaped, cleft or forked laminæ; lobes bear on the
summit other laminæ or leaflets divided in the same manner.
^P. Brodiæi.^ Stem less branched and leaf-expansions broader and
larger than in /P. membranifolia/; laminæ wedge-shaped and deeply
lobed. (Plate XIX.)
GENUS ^Sternogramme^
^S. interrupta.^ Frond a thin membrane repeatedly forked, widely
spreading, divisions one fourth to one half of an inch wide;
fertile plants have the spores arranged in an interrupted line
through the center of the segments resembling a midrib; frond two
to eight inches high; bright red. It is found on the California
coast. The illustration shows a plant on which the hydroid
/Sertularia pumila/ is growing. (Plate XIX.)
GENUS ^Gymnogongrus^
^G. Norvegicus.^ Frond two to four inches high, thin but leathery
in substance, flat, narrow, divided in a regular forking manner;
spreading ends of terminal forks obtuse; axils rounded; spores form
spherical masses in the upper segments, and project on both sides
like hemispheres. It resembles a simple form of /Chondrus crispus/,
but is more delicate. The color is red or purple. This species is
found in deep tide-pools from New York northward. (Plate XIX.)
GENUS ^Ahnfeldtia^
^A. plicata.^ Frond coarse, stem-like filaments, stiff, wiry,
irregularly and profusely branched; sometimes regularly forked and
upper segments equal; entangled; six to eight inches long; tufts
several inches in diameter; dark purple or black. Specimens long
exposed on the beach are faded to white. It is very common from New
York northward. (Plate XIX.)
GENUS ^Callophyllis^
^C. variegata.^ Deeply cleft, wide-spreading, flat, membranaceous
frond; all parts notched more or less angularly; color dark to
bright red; spores form hemispherical warts on surface. Some
varieties differ from this one in having long and narrow, and
others in having short and broad segments. It is a beautiful and
common alga on the Pacific coast, resembling /Euthora/ of the
eastern coast. (Plate XX.)
^C. laciniata.^ Frond deeply cleft; segments wedge-shaped. It is
found on the Pacific coast. (Plate XX.)
[Illustration: PLATE XIX. Phyllophora Brodiæi. Sternogramme
interrupta. Gymnogongrus Norvegicus. Ahnfeldtia plicata.]
[Illustration: PLATE XX. Callophyllis variegata. Callophyllis
laciniata. Iridæa. Cystoclonium cirrhosa.]
GENUS ^Iridæa^
Frond rises from stalk and widens into a flat, thick, leathery, oval
expansion, one to two feet long, and one to three inches broad;
[pg083] simple or lobed; surface sometimes roughened by collections
of spores in dots; dark red, often glittering in the water with blue
and purple tints. It is found on the Pacific coast. (Plate XX.)
SUBORDER ~RHODOPHYLLIDEÆ~
GENUS ^Cystoclonium^
^C. purpurascens.^ The translucent, fleshy, juicy main stem, one
eighth of an inch or less in diameter, runs through the whole
plant; irregularly branched all around main stem; branches again
branch in same manner; branches attenuated at the base, and taper
to a long point; smaller branches distended in places by spores
into bladder-like swellings, hence the name; color rose-red to
dark purple; plants exposed on the beach often faded to orange
and white; six to eighteen inches long. It grows on rocks between
tide-marks as well as in deep water. With the exception of
/Ceramium rubrum/, this is the most common red alga on the eastern
coast from New York northward. It differs from /Rhabdonia/ in
having bladdery branches; otherwise it is easily mistaken for it.
^C. cirrhosa.^ Ends of branches terminate in spirals like tendrils;
otherwise identical with /C. purpurascens/. (Plate XX.)
GENUS ^Euthora^
^E. cristata.^ Frond one inch to five inches high, membranaceous,
broadly spreading; divisions wide and numerous, ultimately becoming
fine like minute branchlets, each one of which, under a glass,
shows a notch in the tip. This beautiful, bright-red alga is found
in abundance north of Cape Cod. It differs from /Delesseria alata/
in having no midrib or veins. It grows in deep water on stones,
shells, and algæ. (Plate XXI.)
GENUS ^Rhodophyllis^
("/Rosy leaf/")
^R. veprecula.^ Frond two to five inches long, one fourth of an
inch to one and one half inches broad, membranaceous, forked;
margin covered with leaflets which are in turn edged with minute
branchlets; color deep red. It is found on the northern New England
coast. (Plate XXI.)
GENUS ^Rhabdonia^
("/A wand/")
^R. tenera.^ Frond six to eighteen inches long, cylindrical,
fleshy, translucent, juicy; irregularly and profusely branched,
branches longest at the base, erect, tapering at both ends,
numerous branchlets; sometimes the main stem runs through
the plant, sometimes it is lost in the [pg084] branching;
spore-masses sometimes form knotty bunches on the side of
branches. It resembles a large /Cystoclonium purpurascens/. It is
characteristic of Long Island Sound, and is not found north of
Cape Cod, but common from there southward along the whole Atlantic
coast. (Plate XXI.)
^R. Coulteri.^ This species is common on the Pacific coast, and
differs from /R. tenera/ in having a more pronounced leading stem,
and branches shorter and crowded at the top of the frond.
GENUS ^Eucheuma^
^E. isiforme.^ Frond grows in tufts a foot or more in diameter;
stems branch in all directions from a central point, and taper
gradually to the end; secondary branches spread to all sides;
all branches swollen at intervals and armed with several spines
spreading from a conical base; color dark red, becoming on exposure
orange or yellow, and at length semi-transparent and horn-like;
substance firmly cartilaginous. Abundant at Key West.
ORDER =RHODYMENIACEÆ=
SUBORDER ~SPHÆROCOCCEÆ~
GENUS ^Gracilaria^
^G. multipartita^ ("many times divided"). Frond four to twelve
inches long; starting from a short, cylindrical stem, it flattens
and broadens as it rises, dividing in an irregular, forking manner,
or cleft into palmate segments which broaden as they rise, and
which divide in the same manner; often cleft or branched on the
edges; conical spore-masses scattered over the frond during July
and August; dingy purple in color. The plant is variable and
sometimes is difficult to determine. It is common from Cape Cod
southward. A narrow variety is most abundant in Long Island Sound.
In Florida and on the California coast there are broad varieties
which may be mistaken for /Rhodymenia/. (Plate XXI.)
GENUS ^Hypnea^
^H. musciformis^ ("moss-like"). Frond six to twelve inches long;
main stem running through, thick below and tapering to the size of
a bristle; much and irregularly branched, especially at the base;
branches wide-spreading in every direction, and longest at the
base; branches branch again in the same manner; all parts beset
with short, horizontal spines; color purplish-red. A characteristic
feature, by which the plant can easily be distinguished, is that
the ends of the long branches are naked and are turned over like a
hook, or nearly twisted. It is found washed ashore, often in large,
intricately twisted tufts, from Cape Cod southward and on the
Pacific coast.
[Illustration: PLATE XXI. Euthora cristata. Rhodophyllis veprecula.
Rhabdonia tenera. Gracilaria multipartita.]
[Illustration: PLATE XXII. Rhodymenia palmata. Rhodymenia palmata.
Lomentaria Baileyana. Chylocladia articulata.]
SUBORDER ~RHODYMENIEÆ~
GENUS ^Rhodymenia^
("/Red membrane/")
^R. palmata^ ("hand-shaped"). The plant commonly known as dulse.
Frond rises from a disk in a short cylindrical stem which spreads
into a thin, broad, fan-shaped membrane six to twelve inches long
and four to eight inches wide at the top; deeply and irregularly
cleft into many wedge-shaped segments; margin usually entire, but
often with leaflets; ends of segments indented, showing where
divisions will ultimately occur; color dark purplish-red. It grows
on rocks and on algæ below low-water mark, and is common on the New
England and California coasts. This is an edible alga, and, like
/Chondrus crispus/, is an article of food in seaports. (Plate XXII.)
GENUS ^Lomentaria^
^L. Baileyana.^ Fronds two to five inches high; grows in tufts;
filaments tubular, irregularly branched; branchlets often all on
one side; branches and branchlets curved or arched, and tapered at
both ends; color brownish-red. It is found washed ashore from Cape
Cod southward. (Plate XXII.)
GENUS ^Champia^
^C. parvula.^ Frond two to six inches long, irregularly branched;
grows in tufts; filaments hollow and constricted, so that they
appear somewhat like a string of beads; color brownish-purple. It
is found washed ashore from Cape Cod southward. (Plate XXIII.)
GENUS ^Chylocladia^
^C. articulata.^ Frond filamentous, three to twelve inches long,
hollow, constricted at intervals; branches emanate from constricted
joints; has the appearance of a series of pink, delicate, oval
sacs. (Plate XXII.)
GENUS ^Plocamium^
^P. coccineum^ ("scarlet"). Frond a flat, semi-cartilaginous main
stem one eighth of an inch, or less, wide, three to eight inches
long, with alternate branches of unequal length emanating from the
edges; branches have alternate branchlets arranged in groups of
three or four in a row; branchlets have pinnulæ on the upper side,
like the teeth of a comb (this peculiarity in branching makes the
genus easy to identify); color dark lake-red. It is not found on
the eastern coast, but is plentiful in California. (Plate XXIII.)
SUBORDER ~DELESSERIEÆ~
GENUS ^Nitophyllum^
^N. laceratum.^ Frond expands from narrow base and divides almost
at once into long, narrow, strap-shaped segments; minute leaflets,
showing [pg086] a dot or spore-cluster, occur at intervals on the
margin; plant six to eight inches long; thin and silky in texture.
Abundant on the California coast. (Plate XXIII.)
^N. Ruprechteanum.^ Frond one foot to two feet long, spreading
from narrow base and dividing by forking into deep-cut, broad,
strap-like lobes; top divisions rounded; traversed lengthwise by
parallel veins; margin of the older parts bordered with a narrow
frill of thin ruffled membrane which sometimes extends also over
parts of the surface of the frond; substance somewhat rigid; color
dark red to purple. It is found on the California coast. (Plate
XXIV.)
^N. punctatum.^ Frond six to twenty inches long and of the same
width, dividing in a forking manner; crowded at top; when in fruit,
covered with dark dots; substance thin and silky; color rose-pink.
It is found on the California coast. (Plate XXIV.)
GENUS ^Grinnellia^
(/Named for Mr. Henry Grinnell of New York/)
^G. Americana.^ Frond a delicate membrane, rose-red or purplish in
color, leaf-shaped, four to eight inches long, one inch to four
inches wide, tapering at both ends; margin entire, but much waved;
a line of darker color through the center resembles a midrib;
masses of spores form dots or specks irregularly over the whole
surface; grows from a disk and short slender stem in bunches on
shells and stones in deep water. It is found washed ashore from
Cape Cod southward, and is luxuriant in New York Bay, where it can
be found at any season, but is in perfection in August. (Plate
XXIV.)
GENUS ^Delesseria^
^D. sinuosa.^ Delicate, leaf-like membrane, with midrib and veins,
much indented and resembling in general outline an oak-leaf; four
to eight inches long, two to four inches broad; short stem; color
dark red, often flecked with green. It grows in bunches in deep
water, and is easily distinguished, since it is the only alga
having a midrib and veins, and resembling the leaf of a tree. It is
found washed ashore from Cape Cod northward. (Plate XXIV.)
^D. alata^ ("winged"). Frond rises from short stem, which flattens
and divides irregularly into many branches and appears like a
midrib, all bordered with narrow membrane one eighth of an inch to
one inch wide; frond two to four inches long; color light red or
pink. It is found on the shore from Cape Cod northward. (Plate XXV.)
^D. Leprieurii.^ Frond one inch to two inches long, very narrow,
with delicate midrib, forked, constricted at intervals; branches
start from constricted points; thin and delicate; color purple.
It is found in tidal rivers near New York, and is common on the
southern coast. (Plate XXV.)
[Illustration: PLATE XXIII. Champia parvula. Champia parvula,
magnified. Plocamium coccineum. Nitophyllum laceratum.]
[Illustration: PLATE XXIV. Nitophyllum Ruprechteanum. Nitophyllum
punctatum. Grinnellia americana. Delesseria sinuosa.]
[Illustration: PLATE XXV. Delesseria alata. Delesseria Leprieurii.
Polysiphonia fastigiata (on Ascophyllum). Polysiphonia parasitica.]
[Illustration: PLATE XXVI. Polysiphonia dendroidea. Polysiphonia
dendroidea, a piece magnified. Polysiphonia Harveyi. Polysiphonia
Harveyi, a piece magnified.]
SUBORDER ~RHODOMELEÆ~
The genera included in this suborder are easily distinguished when in
fruit by the spore-cases, or cystocarps, which appear [pg087]
like little balls, either adherent to the branches, or raised on
short stalks. It is the largest group, and contains many of the most
beautiful of the red algæ.
GENUS ^Polysiphonia^
("/Many tubes/")
A filament of ^Polysiphonia^ appears, when seen under the microscope,
like a bundle of filaments made up of a central tube, or axis,
surrounded by a number of other tubes. It is by the number of these
parts, called siphons, which vary in number from four to twenty, that
the species is determined. In some plants the siphons are surrounded
by a layer of cells, called corticating or bark cells, which give
the filaments a solid, uniform appearance. In others the siphons are
naked, and the filaments then seem striped or banded with color. It
is difficult, without a microscope, to be sure of the classification.
There are, however, other characteristics which separate many of the
species, and some of these are described below. Two hundred species
of /Polysiphonia/ have been named by algologists. The plants are
plentiful on all shores, especially in warm, shallow waters. Some
species are perennial, but most of them are annuals and disappear in
winter.
^P. fastigiata.^ This species grows on /Ascophyllum nodosum/ in
a globular tuft, and appears like a dark-brown ball, one inch
to three inches in diameter. The frond is a dense mass of rigid
filaments branching many times in a forking manner and at broad
angles. The ends are of nearly equal length, giving the plant
a spherical shape. It is common from New York northward at all
seasons, and is easily recognized by its general form and place of
growth. Egg-shaped cystocarps, or spore-cases, occur in the ends of
the terminal filaments. (Plate XXV.)
^P. nigrescens.^ Frond three to twelve inches long, rigid below,
soft above; main stem thick as a bristle, but not always easy to
distinguish; branches alternate and densely branched at the ends;
siphons twelve to sixteen in number; filaments banded; color black
or very dark brown. (Plate XXVII.)
^P. parasitica.^ Frond one inch to three inches long; branched in
a pinnate or feather-like manner; filaments flat; all branches
and branchlets emanating from the edges and on the same plane,
giving a flat frond; color reddish-brown; resembles a fine /Ptilota
plumosa/; cystocarps on short stalks. It is found on the California
coast. (Plate XXV.)
^P. dendroidea.^ This is a variety of the species /P. parasitica/.
Frond four to five inches long; main branches placed at irregular
intervals, but the secondary branches at regular intervals and
alternate; branches [pg088] set at acute angles, giving the plant
a slender appearance; color black or dark brown. It is common on
the California coast. (Plate XXVI.)
^P. Baileyi.^ Frond three to six inches high, flat; branches
emanate from edges of the flat stems; main branches wide-spreading
and irregularly placed, secondary branches regular and alternate;
branchlets one eighth to one half of an inch long, covered on the
edges and around the top with incurved ramuli; branchlets broken
off near the base of the branches in mature plants; branchlets
usually uniform in length, but occasionally one is longer and
branches like the primary stem; color black. Common on the
California coast.
^P. Harveyi.^ Frond two to six inches high; grows in globose tufts,
and has a bushy aspect; branches stiff and wide-spreading; stems
and branches beset with simple or branched spine-like branchlets;
color dark brown, or black when dry; does not collapse when taken
from the water; cystocarps on short stalks; siphons four in number.
It grows on eel-grass and algæ, and is common in Long Island Sound
and northward. Called locally /niggerhair/. (Plate XXVI.)
^P. Olneyi^ (dough-balls). Fronds two to five inches high, densely
tufted; soft filaments of hair-like fineness, much branched, and
spreading; when in fruit covered with tiny balls or cystocarps;
siphons four in number. It is common from Cape Cod to New York.
^P. fibrillosa.^ Frond four to ten inches high, rather robust
below; main stem quickly lost in a number of prominent stems and
spreading branches; irregularly and profusely branched, becoming
ultimately very fine; numerous branchlets covered with colorless
fibrils in hairy tufts, which give it a misty appearance; fibrils
so delicate that they do not show well in dried specimens, but a
distinct feature by which to recognize the species in the young
plant; color light to dark brown; cystocarps adherent to branchlets
or on short stalks; siphons four in number; main branches only
corticated. It is common in summer on stones and on eel-grass, at
low-water mark, from Cape Cod to New York. (Plate XXVII.)
^P. violacea.^ Fronds six to twenty-four inches high, pyramidal
in general outline; main axis with long, wide-spreading branches
at the base; branches rather robust and naked below, but numerous
and becoming very fine and tufted at top; cystocarps adherent or
on short stalks; siphons four in number; main stems corticated;
ultimate branchlets show articulations; color brownish-red. It is
common from New York northward. (Plate XXVII.)
^P. urceolata.^ Frond three to ten inches high; main stem
bristle-like; branches naked below, divided and subdivided above;
branches with short branchlets set at a wide angle and often
recurved; siphons four in number; shows articulations; color deep
red. Name refers to cystocarp, which resembles a pitcher. The plant
grows in loose tufts, and is common from New York northward and on
the California coast.
Variety ^formosa^. Filaments soft and finer than in /P. urceolata/;
branches long and flexuous; articulations five to ten times longer
than broad; color bright red. It grows in tufts sometimes a foot
long, and is found only in the spring.
[Illustration: PLATE XXVII. Polysiphonia nigrescens. Polysiphonia
fibrillosa. Polysiphonia violacea. Polysiphonia Woodii.]
[Illustration: PLATE XXVIII. Laurencia pinnatifida. Dasya elegans.
Dasya plumosa. Dasya plumosa, magnified.]
^P. variegata.^ Fronds four to ten inches high; filaments thick as
a bristle below, and branched in a forking manner to the very top;
divided at long intervals below, at the top becoming of hair-like
fineness [pg089] and dividing rapidly, forming a densely
tufted mass, which collapses when taken from the water; color
purple-brown; when mounted, silky in appearance; filaments banded;
siphons six in number. It forms purple tufts on woodwork and on
eel-grass from Cape Cod southward.
^P. Woodii.^ Fronds four to six inches high; branches flat, long,
wide-spreading, emanating from the edges in one plane; younger
branches show articulations; ultimate branchlets inclined to curve
inward; color light brown. Found on the California coast. (Plate
XXVII.)
GENUS ^Laurencia^
^L. pinnatifida.^ Frond flat, thick, leathery; main stem with
opposite, or alternate, branches of about the same size and
character as itself; all pinnatifid, or cut on the edges into
branchlets, some of which are again divided; color bright purple,
often unevenly faded. It is found on the Pacific coast. (Plate
XXVIII.)
GENUS ^Dasya^
Chenille-weed.
^D. elegans.^ Fronds from six inches to three yards long; main stem
and branches cylindrical, and all densely clothed with a fine,
hair-like fringe, which gives the plant the appearance of chenille;
cystocarps on stalks along the branches; color pink or lake-red.
Out of water it seems like a mass of purple jelly. It is found at
or just below low-water mark from Cape Cod southward, and is very
plentiful in New York Bay. (Plate XXVIII.)
^D. plumosa.^ A species found on the California coast. The fringe
covering the stems consists of minute leaflets instead of hairs, as
in /D. elegans/. (Plate XXVIII.)
GENUS ^Bostrychia^
^B. rivularis.^ Fronds one inch high; color dark purple; branches
fine and irregularly bent. It grows where the water is not very
salt, and is found in patches on submerged logs near New York.
Common from Charleston, South Carolina, southward. (Plate XXIX.)
GENUS ^Rhodomela^
^R. subfusca.^ Frond six to eighteen inches long; main stem
cylindrical, and branching widely on all sides; branches longest
at base and gradually shortening to the top of the stem; branches
naked below, but at the ends profusely branched, forming tufts of
branchlets. It is a perennial plant, and changes in aspect with
the season. When mature it is stiff and coarse, and when dry it is
quite black. Common from New York northward.
^R. Rochei.^ This species resembles in form /R. subfusca/, but
is much finer and more delicate. In spring it is a soft, fine,
feathery, and beautiful [pg090] alga of a red-brown color. It
is found washed ashore, or in deep tide-pools, south of Cape Cod.
(Plate XXIX.)
^R. larix.^ Frond cylindrical, robust, six to fourteen inches high;
branches of unequal length standing out horizontally all around the
main stem; clusters of branchlets growing spirally around stem and
branches. Found on the northern California coast. (Plate XXIX.)
^R. floccosa.^ Frond four to ten inches high; less robust than /R.
larix/; stem and branches flat and divided in one plane; branches
alternate; ultimate branchlets somewhat incurved; color black. In
fertile plants the terminal branchlets are gathered in a mass.
Found on the California coast. (Plate XXIX.)
GENUS ^Chondria^
Plants of this genus are distinguished by having the ultimate
branches attenuated at the base.
^C. dasyphylla.^ Frond four to eight inches high; general outline
pyramidal; branches alternate on main stem; stem and branches
covered with short, club-shaped (blunt at top, attenuated at base)
branchlets; cystocarps, or spore-cases, adherent to branchlets or
on short stalks; color light or dull brown. It grows in tufts, and
is common from New York to Cape Cod. (Plate XXX.)
^C. tenuissima.^ This species is similar to /C. dasyphylla/, but
is more slender, and the branchlets taper at both ends instead of
being club-shaped.
^C. striolata.^ A species similar to /C. tenuissima/. The
branchlets bear secondary branchlets, and the cystocarps are on
short stalks. It is plentiful in Long Island Sound.
SUBORDER ~CERAMIEÆ~
GENUS ^Callithamnion^
These are very beautiful and delicate plants, growing in small,
soft, silky tufts, bright red in color, with darker dots along the
much-branched filaments. There are many species, and they are common
on the northern shores of both oceans; but the different species are
not easy to distinguish with the naked eye, and so but a few of them
are described below. The special characteristics by which the genus
may be recognized are: fronds filamentous, of cobweb fineness, one
inch to six inches long, much branched, and closely crowded at the
top; brilliant red color.
[Illustration: PLATE XXIX. Bostrychia rivularis. Rhodomela Rochei.
Rhodomela larix. Rhodomela floccosa.]
[Illustration: PLATE XXX. Chondria dasyphylla. Callithamnion
americanum. Callithamnion Pylaisæi. Callithamnion Pylaisæi, a piece
magnified.]
^C. americanum.^ Frond three to six inches long, densely tufted;
filaments of extreme fineness; main branches alternate; much
branched; main and secondary branches have pairs of branched
ramuli along the [pg091] branches; color rose-pink. It grows
on wharves and on algæ below low-water mark, and is a common and
beautiful species. It is found (but only in the spring) from New
York northward, and is abundant in Long Island Sound. (Plates XXX,
XXXI.)
^C. Pylais[oe]i.^ Fronds three to six inches long, more robust
and darker in color than in /C. Americanum/; main and secondary
branches alternate, decompound, all bearing at short intervals
short opposite branchlets, which in turn are covered with ramuli.
It is found in spring on wharves and on algæ from Boston northward.
(Plate XXX.)
^C. Baileyi.^ Fronds one inch to three inches long, with main
stem as thick as a bristle, and running to the top of the frond;
branches around the main stem longer at the base than at the
apex, giving the plant a pyramidal outline; branches also have a
main stem and short branches beset with branchlets; shrub-like in
aspect; color purplish-red. Common in summer from New York to Cape
Cod.
^C. seirospermum.^ Frond two to five inches high, pyramidal in
outline; has main stem and alternate lateral branches; branches
have secondary branches beset with delicate, erect branchlets;
hair-like in fineness. It is common from Cape Cod southward, and is
plentiful in Long Island Sound. (Plate XXXI.)
^C. byssoideum.^ Fronds one inch to three inches long; filaments
very delicate; main branches many times divided; secondary branches
long; many branchlets; rose-colored. It grows in globose tufts, and
is common in Long Island Sound. (Plate XXXI.)
^C. floccosum.^ Fronds three to six inches long, hair-like in
fineness; flaccid; main branches sparingly branched below;
numerous alternate branches above; all clothed with short, simple
branchlets; color dark brownish-red. The plant is so exceedingly
fine that it is difficult to distinguish the divisions. It grows on
eel-grass and on algæ below low-water mark, and is found from New
York to Cape Cod. (Plate XXXI.)
GENUS ^Griffithsia^
(/Named for Mrs. Griffiths, an English algologist/)
These are among the most beautiful of seaweeds, because of their
brilliant color and exceedingly delicate structure. They grow in deep
water, and specimens cast ashore are usually torn and imperfect, but
they may often be gathered from deep tide-pools, and sometimes are
found growing on eel-grass. If placed in fresh water they discharge
their coloring-matter and quickly decompose.
^G. Bornetiana.^ Fronds two to five inches high; filaments jointed,
the divisions being long and pear-shaped, growing shorter as they
near the top; repeatedly forked; very soft and fragile. It grows
in tufts, resembling corals; attains perfection in July, and
disappears later in the summer. Found from Cape Cod southward,
washed ashore after storms. (Plate XXXII.) [pg092]
GENUS ^Ptilota^
Feather-weed.
^P. serrata.^ Fronds three to six inches long, dark red in color,
cartilaginous; flattened main stem with opposite, flattened
branches, one of which is minute, so that it appears like alternate
branching; branches also have lateral branchlets and pinnulæ,
looking like feathers or ferns; all branching in one plane, making
a flat frond. It is found in the drift on the beach after a storm,
and is common from Cape Cod northward, and also on the California
coast. (Plate XXXII.)
^P. elegans.^ Narrower and more delicate than /P. serrata/,
otherwise it has the same essential features. It is common in
summer from New York northward, growing on cliffs, under /Fucus/,
near low-water mark, and it is also found washed upon the beach.
(Plate XXXII.)
^P. densa.^ Frond three to twelve inches high, one eighth of
an inch wide, flat, cartilaginous; has leading stem with flat
alternate branches; branches simple or branched again; edges of
whole plant beset with notched, curved pinnulæ alternating with
smaller feather-like pinnulæ, giving a dense edge to all parts of
the frond. It is found on the California coast. (Plate XXXIII.)
^P. hypnoides.^ Flat, cartilaginous main stem, much branched, and
all beset with pinnulæ. It differs from /P. densa/ in having the
alternate pinnulæ straight and club-shaped, instead of toothed and
curved, and the plant is not so dense and compact. Found on the
California coast. (Plate XXXIII.)
GENUS ^Spyridia^
^S. filamentosa.^ Fronds four to eight inches long; filaments as
thick as bristles, irregularly and repeatedly branched; young
branches show articulations and seem to be striped; all branches
clothed with short, very delicate, transparent filaments, which
give the plant a hazy appearance; color purplish-red, which becomes
brown when dried; does not collapse when taken from the water. It
grows in tufts below low-water mark, and is found in the drift on
the beach from Cape Cod southward. (Plate XXXIII.)
GENUS ^Ceramium^
The pitcher-weed. This genus is easily recognized by the ends of the
filaments, which are forked and incurved, resembling minute pincers
or claws. The filaments are also more or less distinctly banded. It
is widely distributed.
[Illustration: PLATE XXXI. Callithamnion americanum, a piece
magnified. Callithamnion seirospermum. Callithamnion byssoideum, var.
fastigiatum. Callithamnion floccosum.]
[Illustration: PLATE XXXII. Griffithsia Bornetiana. Ptilota serrata.
Ptilota serrata, magnified. Ptilota elegans.]
[Illustration: PLATE XXXIII. Ptilota densa. Ptilota hypnoides.
Ptilota hypnoides, magnified. Spyridia filamentosa.]
^C. rubrum^, red ceramium. This is a very common and robust
species, found everywhere, and growing on everything. It is
variable in appearance, becoming quite coarse when old, the
incurving, claw-like ends, which are characteristic of the genus,
being less pronounced. It branches by repeated forking, and, under
the microscope, shows a bark-like [pg093] layer of cells over
the whole surface, which make the ring-like bands on the filaments
less conspicuous.
[Illustration: PLATE XXXIV. Ceramium rubrum, var. proliferum.
Ceramium rubrum, top of frond magnified. Ceramium diaphanum.
Ceramium tenuissimum, var. patentissimum.]
Variety ^proliferum^. Fronds beset on all sides with simple or
forked branchlets. (Plate XXXIV.)
Variety ^secundatum^. Branchlets generally arranged on one side of
the filaments, or secund.
^C. strictum^ ("straight"). Brown or purplish-red filaments of
hair-like fineness, growing in tufts two to six inches high,
branching in narrow forks more and more closely as they reach the
top of the frond. There are no principal branches, the filaments
being of about the same diameter and regularly dividing in a
forking manner throughout. The filaments are banded, the red rings
being relatively very narrow. The white interstices at the base are
several times longer than broad, but shorten gradually until at the
top they are of equal length with the red bands. This species is
common from Cape Cod to New York.
^C. diaphanum.^ This species has comparatively stout leading
branches, with secondary alternate branches which are finer than
the main stems and divide in a forking manner throughout, and
ultimately become very fine. The color is brown or purplish-red,
distinctly banded. It grows on eel-grass and algæ, and is found
from Cape Cod to New York. (Plate XXXIV.)
^C. fastigiatum.^ Filaments of hair-like fineness and of about same
size throughout; branched in regular forking manner throughout,
the divisions being wide and distant at the base, but gradually
becoming closer and narrower as they reach the top; the upper
segments about equal, giving a level top and regular outline in
mounted specimens; the terminal forks erect, or less incurved than
in other species; small points or branchlets emanate from some of
the nodes or joints between the bands of color; tufts globe-shaped,
two to five inches high; color lake-red. This species grows on
mud-flats and mud-covered rocks as well as on algæ and eel-grass.
^C. tenuissimum.^ Fronds two to four inches high, densely tufted;
the forked divisions very wide or open; color rose-pink.
Variety ^patentissimum^. Fronds small; the forked divisions distant
and very wide open. A mounted specimen appears somewhat like
network. The species is common in Long Island Sound. (Plate XXXIV.)
GENUS ^Microcladia^
^M. Coulteri.^ Cylindrical, slightly flattened main stem; branches
set uniformly and alternately, short at the base, gradually
lengthening as far as the center, and from there diminishing to
the apex of the stem, giving a leaf-like outline. The same mode
of branching and the same outline are repeated in the branches.
The ultimate divisions are like forked divisions, and are somewhat
incurved. The plant is six to eight inches high, and in color is
of many shades of red and pink. It is found in abundance on the
Pacific coast at all seasons. (Plate XXXV.)
^M. borealis.^ Branches and branchlets placed on one side of arched
main stems; secondary branches curved in opposite direction and
bearing branchlets, also divided on one side only; color dark
brown. It is found on the northern Pacific coast. (Plate XXXV.)
[pg094]
ORDER =CRYPTONEMIACEÆ=
SUBORDER ~GLOIOSIPHONIEÆ~
GENUS ^Gloiosiphonia^
("/Viscid tube/")
^G. capillaris.^ Frond six to ten inches high, solitary or in
tufts; main stem cylindrical, solid above, hollow below; from about
an inch above the base densely beset with short, wide-spreading
branches arranged evenly and all around the stem; branches again
branched in the same way; branches and branchlets attenuated at
base and apex; soft, tender, juicy; shrinks much in drying. The
species is easily recognized by its delicate gelatinous substance,
tapering branchlets, and brilliant red color. It is found in early
summer in tide-pools on the New England coast.
SUBORDER ~GRATELOUPIEÆ~
GENUS ^Halymenia^
^H. ligulata.^ Frond membranaceous, repeatedly and regularly
divided in a forking manner; the larger divisions one half of an
inch wide and growing very narrow at the top; four to five inches
high, spreading in a fan-shape; color rose-red. It is found at Key
West.
GENUS ^Grateloupia^
^G. Cutleria.^ Frond coarse, flat, variable; either simple,
long, and narrow, or short and broad, tapering at both ends, or
blunt at the apex, or deeply cleft into many segments; sometimes
with leaflets along the edges; height two to three feet; color
reddish-brown; in fading, changes to purple and green, and may be
variegated. When simple, the plant resembles /Iridæa/. Found on the
northern California coast.
GENUS ^Prionitis^
^P. lanceolata.^ Frond narrow, flat, smooth; leathery stems, which
branch irregularly and sparingly from the edges; branches bordered
with lance-shaped leaflets; color dark brownish-red; plant ten or
more inches high, and varies considerably. (Plate XXXV.)
There are other species, among them ^P. Andersonii^ (Plate XXXVI.);
all are easily distinguished by the lance-shaped leaflets. Common
on the Pacific coast.
[Illustration: PLATE XXXV. Microcladia Coulteri. Microcladia
Coulteri, magnified. Microcladia borealis. Prionitis lanceolata.]
[Illustration: PLATE XXXVI. Prionitis Andersonii. Pikea Californica.
Halosaccion ramentaceum. Polyides rotundus.]
SUBORDER ~DUMONTIEÆ~
GENUS ^Pikea^
^P. Californica.^ Divisions of frond thick, narrow, cartilaginous;
central axis one eighth of an inch to one inch wide, three to four
inches high, thickly set with similar branches irregularly placed;
all bordered [pg095] with numerous forward-pointing branchlets,
which in turn have spine-like ramuli of various lengths; frond
flat, broadly spreading; dark red. It is common at all seasons on
the California coast. (Plate XXXVI.)
GENUS ^Halosaccion^
^H. ramentaceum.^ Fronds brownish-purple, six to fourteen inches
long, coarse and cartilaginous, cylindrical, hollow, compressed,
attenuated at the base; more or less covered with simple or forked
hollow branches half the size of the main stem. In exposed pools
the plants are short and densely branched; in sheltered places they
are larger and more delicate in texture. They are common on the
northern New England and northern California coasts. (Plate XXXVI.)
SUBORDER ~RHIZOPHYLLIDEÆ~
GENUS ^Polyides^
^P. rotundus.^ Frond three to six inches high, cylindrical,
cartilaginous, repeatedly forked, ends obtuse; spore-masses form
numerous lighter-colored excrescences on the upper divisions of the
frond; dark red. Common from New York northward, in deep pools and
washed ashore. (Plate XXXVI.)
SUBORDER ~SQUAMARIEÆ~
GENUS ^Peyssonnelia^
^P. Dubyi.^ Frond completely adherent to the rock or stone on
which it grows; color dark purple; somewhat calcareous; redder and
thicker than next species. It is found at low-water mark or in deep
water on the northern New England and northern California coasts.
GENUS ^Petrocelis^
^P. cruenta.^ Frond closely adherent, forming dark-purple velvety
patches of indefinite outline on rocks and stones. Common north of
Cape Cod.
GENUS ^Hildenbrandtia^
^H. rosea.^ Forms continuous pink incrustations of considerable
extent on stones and rocks at low-water mark. Common everywhere.
SUBORDER ~CORALLINEÆ~
The genera of this suborder are characterized by a calcareous or
stony incrustation of the fronds, which gives them the appearance of
corals. Most of the species are tropical. [pg096]
GENUS ^Corallina^
("/Coral-like/")
^C. officinalis^, common coralline. Frond grows from a disk in
tufts more or less dense. The plant is rigid, and seems like
jointed, branched coral. The articulations are cylindrical at the
base, wedge-shaped and flattened above. Branches emanate from the
top of the articulations. The color varies from reddish-purple to
gray-green, and is often bleached white when exposed to the sun.
Common in tide-pools and on rocks at low-water mark from New York
northward. (Plate XXXVII.)
GENUS ^Melobesia^
This genus will attract attention, although it cannot be gathered. It
is a thin, brittle, scaly substance of indefinite form, which expands
horizontally and resembles a lichen. It forms brown and pink crusts
on other algæ and on rocks, stones, and shells.
ORDER =BANGIACEÆ=
GENUS ^Bangia^
^B. fusco-purpurea^ ("brown-purple"). Fine, hair-like, unbranched,
dark-purple filaments, one inch to six inches long. It grows in
large patches on rocks and woodwork, floating free, but falling
into soft, silky, fleece-like masses when left by the tide. Common
on northern shores. (Plate XXXVII.)
GENUS ^Porphyra^
("/Purple dye/")
This plant, except in color, is like the green alga /Ulva/. In
color it is purple of various shades. The species are named from
variations in the outline of the frond. They are found everywhere,
and throughout the year. The plants are edible, being the laver of
commerce, eaten principally by the Chinese, who make them into soup.
^P. vulgaris.^ Frond a broad, thin membrane of purple color, three
to twelve inches across; margin much waved; sometimes attached at
the center, often widely expanded and folded, sometimes deeply
lobed. (Plate XXXVII.)
^P. laciniata.^ Differs from /P. vulgaris/ in being divided into
narrow segments or into wavy, ribbon-like forms. (Plate XXXVII.)
[Illustration: PLATE XXXVII. Corallina officinalis. Bangia
fusco-purpurea. Porphyra vulgaris. Porphyra laciniata.]