ovate or oblong, acutish; carpels rounded at base and slightly grooved
on the back, the edges acute.--Salt-marshes along the coast, Lab. to
N. J., and in saline places in the interior across the continent. (Eu.,
Asia, etc.)
2. SCHEUCHZERIA, L.
Sepals and petals oblong, spreading, nearly alike (greenish-yellow), but
the latter narrower, persistent. Stamens 6; anthers linear. Ovaries 3,
globular, slightly united at base, 2--3 ovuled, bearing flat sessile
stigmas, in fruit forming 3 diverging and inflated 1--2 seeded pods,
opening along the inside.--A low bog-herb, with a creeping jointed
rootstock, tapering into the ascending simple stem, which is zigzag,
partly sheathed by the bases of the grass-like conduplicate leaves, and
terminated by a loose raceme of a few flowers, with sheathing bracts;
leaves tubular at the apex. (Named for _John_ and _John Jacob
Scheuchzer_, distinguished Swiss botanists early in the 18th century.)
1. S. palustris, L.--Peat-bogs, N. Brunswick to N. J., westward across
the continent. June. (Eu., Asia.)
3. POTAMOGETON, Tourn. PONDWEED.
Flowers perfect. Sepals 4, rounded, valvate in the bud. Stamens 4,
opposite the sepals; anthers nearly sessile, 2-celled. Ovaries 4 (rarely
only one), with an ascending campylotropous ovule; stigma sessile or on
a short style. Fruit drupe-like when fresh, more or less compressed;
endocarp (_nutlet_) crustaceous. Embryo hooked, annular, or cochleate,
the radicular end pointing downward.--Herbs of fresh, or one in
brackish, ponds and streams, with jointed mostly rooting stems, and
2-ranked leaves, which are usually alternate or imperfectly opposite;
the submersed ones pellucid, the floating ones often dilated and of a
firmer texture. Stipules membranous, more or less united and sheathing.
Spikes sheathed by the stipules in the bud, mostly raised on a peduncle
to the surface of the water. (An ancient name, composed of [Greek:
potamo/s], _a river_, and [Greek: gei/ton], _a neighbor_, from the place
of growth.)--By _fruit_, the full-grown fresh or macerated fruit is
intended; by _nutlet_, that with the fleshy outer portion or epicarp
removed. All except n. 19 flower in summer; the month mentioned
indicates the time of ripening of the fruit.
Sec. 1. _Leaves of two sorts; floating ones more or less coriaceous, with a
dilated petioled blade, different in form from the thinner submersed
ones._
[*] _Submersed leaves reduced to narrowly grass-like or filiform sessile
phyllodia._
[+] _Stems rather stout; stipules free; spikes all emersed, cylindrical
and densely fruited; fruits fleshy and turgid, obliquely obovate._
1. P. natans, L. _Stem simple or sparingly branched_; floating leaves
all long-petioled, elliptical or ovate, somewhat cordate at base, obtuse
but with a blunt point, 21--29-nerved; upper submersed leaves
lanceolate, early perishing, the lower (later in the season) very
slender (3--7' long, barely 1'' wide); upper _stipules very long, acute;
peduncle about the thickness of the stem_; spikes 1--2' long; sides of
the turgid _nutlet with a small deep impression in the middle_; embryo
coiled into an incomplete elliptical ring.--Ponds and ditches, N. Scotia
to Va., westward across the continent. In deeper or flowing water the
plant becomes more slender and often wholly submersed (var. PROLIXUS,
_Koch_).--Aug., Sept. (Eu., Asia.)
2. P. Oakesianus, Robbins. Stem more slender, _much branched_; floating
leaves smaller (1--11/2' long), ovate- or oblong-elliptical, obtuse,
fewer-(17--23-) nerved; lowest submersed ones almost capillary (only
1/4--1/2'' wide), continuing through the flowering season; spikes shorter
(3/4--1' long), on _peduncles much thicker than the stem_; fruit smaller
and more acute; _sides of the turgid nutlet not at all impressed_;
curvature of the embryo nearly circular, its apex directed to a point
above its base.--Ponds, and especially pools and stagnant ditches, Mass.
to N. J.; also Anticosti. Aug.
3. P. Pennsylvanicus, Cham. _Stems compressed_, often simple from the
creeping rootstocks; floating leaves chiefly opposite (1--31/2' long),
11--17-nerved, oblong, tapering into a _short petiole_, the lower
gradually narrowing and passing into the submersed ones, which are very
numerous and approximate, 2-ranked, linear (2--5' long, and 1--21/2''
wide), 5--7-nerved, the lateral nerves slender and nearly marginal, the
space within the inner nerves _coarsely cellular-reticulated; stipules
very obtuse_; spikes numerous, about the length of the thickened
peduncle; _fruit round-obovate_, flattish, 3-keeled when dry; _nutlet
distinctly impressed on the sides_; curvature of the embryo transversely
oval. (P. Claytonii, _Tuckerm._)--Still or flowing water, N. Brunswick
to S. C., west to N. Ind. and Minn. July, Aug.
[+][+] _Like the preceding section, but all the parts small, slender and
delicate, only the fertile plants producing floating leaves; spikes very
small and few-flowered; propagated by autumn buds._
4. P. Vaseyi, Robbins. Very delicate; stem almost capillary; _floating
leaves obovate_ (3--5'' long) and about the length of their filiform
petioles, with 5 nerves deeply impressed beneath, cross-veins distinct;
submersed leaves filiform-linear, very attenuate (1--2' long, {1/8}--1/4''
wide) and acute; _stipules_ not adnate, scarious, _long_, acute; spikes
all emersed, few, interrupted-oblong, 3--5-flowered, on a thickish
peduncle; fruit oblique, round-obovate ({2/3}'' long), compressed,
slightly sharp-margined, tipped with a distinct recurved style, the
sides impressed and face acute; upper portion of the embryo circularly
incurved, its apex transverse to the fruit.--Canada and N. Eng.; also
Ill. The fruiting form, with floating leaves, rare; the submerged form
apparently much more abundant.
5. P. lateralis, Morong. Stem filiform, branching; _floating leaves
elliptical_ (4--6'' long by 2'' wide), with 5--7 nerves deeply impressed
beneath, tapering at base into a somewhat dilated petiole shorter than
the blade; _submersed leaves linear_, acute (1--3' long by 1/4--1/2'' wide),
1--3-nerved, the mid-nerve with fine veins or cellular reticulations on
each side, bi-glandular at base; _stipules short; peduncles with a very
peculiar lateral appearance_, widely spreading at maturity, sometimes
even recurved, often thicker than the stem; spikes often interrupted
(2--4-flowered); fruit obliquely obovate (hardly 1'' long), the back
much curved, with two fine grooves upon it; embryo oval in its curve,
the apex nearly touching the base.--Mass. and Mich.; rare. Undeveloped
specimens resemble P. pusillus.
[+][+][+] _Stems slender or filiform, much branched; floating leaves
sometimes wanting; stipules adnate to the base of the leaf; spikes of
two kinds, one emersed, cylindrical and many-flowered, on a club-shaped
peduncle, the other submersed, globular and few-flowered; fruit flat,
cochleate, with thin or scarcely any flesh and a thin nutlet; embryo
spiral._
6. P. Spirillus, Tuckerm. Floating leaves oval to lance-oblong and
lanceolate (the largest 10'' long, 4'' wide), usually obtuse, about
equalling the _rather dilated petioles_, with 5--many nerves beneath
deeply impressed; upper submersed leaves either with or without a
lance-oblong or broad-linear proper blade; the numerous lower ones
narrow-linear, tapering toward the obtuse apex (3/4--11/2' long, 1/4--{2/3}''
wide); stipules early lacerate; _submersed flowers usually solitary on
very short erect peduncles; fruit_ with the back either _winged and with
4--5 distinct teeth or wingless and entire; embryo coiled 13/4
turns_.--Rivers, and even far up small streams, N. Eng. to Va., west to
Mich. and Mo. June--Aug.--Stem less slender than in the next.
7. P. hybridus, Michx. Floating leaves oval to lance-oblong (the largest
10'' long, 6'' wide), often acute, longer than the _filiform petioles_,
with about 5--7 nerves beneath deeply impressed; submersed leaves very
numerous, almost setaceous (1--3' long, very rarely 1/2'' wide); stipules
obtuse; emersed spikes 4--7'' long; _submersed_ spikes 1--4-flowered,
their _peduncles_ (of their own length) _frequently recurved; fruit
minute, about 8-toothed on the margin; embryo coiled 11/2 turns_.--Shallow
stagnant waters, N. Brunswick to Fla., west to Mich., Mo., and N. Mex.
June--Aug.
[*][*] _Submersed leaves lanceolate, rarely oval or linear,
membranaceous; spikes dense, many-flowered, on stout peduncles._
8. P. rufescens, Schrad. Stem simple; floating leaves (often wanting)
2--5' long, rather thin, _wedge-oblanceolate, narrowed into a short
petiole_, 11--17-nerved; _submersed leaves almost sessile_, lanceolate
and lance-oblong, smooth on the margin, fewer-nerved; stipules broad,
hyaline, obtuse, upper ones acuminate; spike 1--2' long, often somewhat
compound; fruit obovate, lenticular, pitted when immature, with an acute
margin and pointed with the rather long style; embryo incompletely
annular.--In streams or ponds, N. Brunswick to N. J., west to Minn. and
Tex. Aug., Sept. (Eu.)
9. P. fluitans, Roth. Stem often branching below; _floating leaves
thinnish, lance-oblong or long-elliptical_, often acute,
_long-petioled_, 17--23-nerved; _submersed leaves very long_ (3--12', by
2--12'' wide), _lanceolate and lance-linear_, 7--15-nerved, coarsely
reticulated; peduncles somewhat thickened upward; fruit obliquely
obovate, obscurely 3-keeled when fresh, and distinctly so when dry, the
middle one winged above and sometimes with 3--5 shallow indentations;
the rounded slightly curved face surmounted by the short style; nutlet
with the sides scarcely impressed; upper part of the embryo circularly
in-curved. (P. lonchites, _Tuckerm._)--In streams or rarely in ponds,
N. Brunswick to N. J., west to Minn. and Iowa. Aug., Sept. (Eu.)
10. P. pulcher, Tuckerm. Stem simple, black-spotted; _leaves of three
kinds_; floating ones becoming very large (41/2 by 31/2'), _roundish-ovate
and cordate or ovate-oblong_, 25--37-nerved, _all alternate; upper
submersed ones (3--5) usually lanceolate_, acute at base and very
long-acuminate, 10--15-nerved, very thin, cellular each side of the
midrib, undulate, short-petioled; _lowest_ (2--4 near the base of the
stem) _thicker, plane, oval or oblong_ with a rounded base, or
spatulate-oblong, on longer petioles; stipules rather short and obtuse;
peduncles thicker than the stem; fruit with a rounded back and angular
face, pointed, distinctly 3-keeled when fresh, sharply so when dry;
nutlet with two deep dorsal furrows, and a sinus below the angle in
front; sides flat; embryo circularly much incurved above.--Ponds, Vt. to
Ga. and Mo. July, Aug.
11. P. amplifolius, Tuckerm. Stems simple, of very variable length;
_floating leaves_ (sometimes wanting) large, _oblong or lance-ovate_,
sometimes slightly cordate at base, abruptly acutish, 30--50-nerved, on
_rather long petioles_; submersed leaves often very large (reaching 7'
by 2'), lanceolate or oval, acute at each end, _usually much recurved,
undulate_, mostly on short petioles; _stipules very long and tapering to
a point_, soon becoming loose; peduncles thickened upward, in deep water
much elongated; fruit very large (over 2'' long), rather obliquely
obovate, 3-keeled, with a broad stout beak; nutlet slightly impressed on
the sides; upper part of the embryo curved into a ring.--Ponds and
rivers, N. Eng. to N. J., west to Minn. and Kan. Aug., Sept.
12. P. Illinoensis, Morong. _Stem stout, branching_ towards the summit;
floating leaves opposite, oval or ovate (2--5' long by 11/2--2' broad),
19--25-nerved, rounded or subcordate at base, with a short blunt point
at apex, on short petioles, _submersed leaves rather few,
oblong-elliptical_, acute at each end, _usually ample_ (largest 8' by
11/2'); _stipules coarse, obtuse, strongly bicarinate_ (2' long);
peduncles often clustered at the summit (2--4' long), thickening upward;
_fruit roundish-obovate_ (13/4--2'' long), 3-keeled on the back, middle
keel prominent; nutlet flattened and slightly impressed on the sides,
obtuse or pointed at base; apex of embryo directed transversely
inward.--Streams and ditches, western N. Y. to Ill., Iowa, and Minn.
Very near the last.
13. P. heterophyllus, Schreb. _Stem slender, very branching_ below;
floating leaves mostly thin, variable, but with a short blunt point,
9--15-nerved, usually 1--2' long and 6--9'' wide; submersed ones usually
lanceolate or linear-lanceolate, acuminate or cuspidate, narrowed toward
the base, about 7-nerved on the stem and 3-nerved on the branches; upper
ones petioled, lower sessile; _stipules obtuse_, loose; peduncles
somewhat thickened upward; fruit small, roundish, compressed, scarcely
keeled; embryo annular above. (P. gramineus, _Fries_.)--Still or flowing
water, common. Varies exceedingly in its submersed leaves, peduncles,
etc.; the var. GRAMINIFOLIUS (Fries), growing in rapid streams, with
stems much elongated and less branched, and the flaccid submersed leaves
2--7' long by 2--10'' wide.
Var. (?) myriophyllus, Robbins. Sending up from running rootstocks many
short repeatedly dichotomous and densely leafy stems; fertile stems very
slender; floating leaves small, delicate, lance-oblong, on long filiform
petioles; submersed stem-leaves larger, early perishing; those of the
branches (deep-green) linear-oblanceolate, very small (3/4--1' long),
acute, sometimes minutely serrulate; spike slender, loosely-flowered,
much shorter than the thickened peduncle.--Apponaug Pond, R. I., without
fruit.
13^a. P. Zizii, Mert. & Koch. Resembling P. lucens, but smaller, much
branched at base; _upper leaves coriaceous or subcoriaceous,
long-petioled_ and _sometimes emersed_, the others subsessile, all
usually numerous, undulate and _shining_; peduncle elongated. (P.
lucens, var. minor, _Nolte_. Also P. gramineus, var. (?) spathulaeformis,
_Robbins_; P. spathaeformis, _Tuckerm._; "P. varians, _Morong_.")--N. Eng
to Fla., and westward. Connecting with the next section. (Eu.)
Sec. 2. _Leaves all submersed and similar, mostly sessile, membranaceous
and dilated, lanceolate, oblong, or oval; stipules obtuse, becoming
loose._
14. P. lucens, L. Stem thick, branching, sometimes very large; _leaves
more or less petioled_, oval or lanceolate, _mucronate_, often rough
serrulate, _frequently shining_; peduncles often elongated; _fruit_
roundish and compressed, _with obtuse margins, slightly keeled_; embryo
circularly incurved above.--Ponds, N. Eng. to Fla., west to the Pacific.
Aug., Sept. (Eu.)
Var. (?) Connecticutensis, Robbins. Stem flexuous; _leaves_ all
submersed, nearly sessile, lanceolate, _acuminate, crisped, not shining
nor serrulate; fruit larger, distinctly keeled_; nutlet thick and
hard.--Lake Saltonstall, East Haven, Conn.
15. P. praelongus, Wulf. Stem very long, branching, flexuous; _leaves_
lance-oblong or lanceolate (sometimes 7' long), _half-clasping, obtuse
with a boat-shaped cavity_ at the extremity, thence splitting on
pressure; stipules scarious, very obtuse; spikes rather loose-flowered;
_peduncles very long_ (sometimes reaching 20'); _fruit_ obliquely
obovate, compressed, _sharply keeled_ when dry; style terminating the
nearly straight face; curve of the embryo oval and longitudinal.--Ponds
and large rivers, N. Scotia to Mass., west to Minn. and Iowa. Sept.,
Oct.--Stem white; foliage bright green. (Eu.)
16. P. perfoliatus, L. Stem branching; _leaves orbicular, ovate or
lanceolate from a cordate-clasping base_, usually obtuse and often
minutely serrulate; peduncles short, cylindrical; _fruit_ irregularly
obovate, _obtusely margined_; embryo incurved in an oval.--Ponds and
slow streams, common. N. Scotia to Fla., west to Minn. and Iowa. Sept.,
Oct. (Eu.)
Var. lanceolatus, Robbins. Larger; _leaves long-lanceolate_ from a
cordate clasping base and _acuminate_, wavy, 3--41/2' long; _peduncles
thickened upward_.--Same range as the species, and extending west to the
Pacific.
17. P. crispus, L. _Stem compressed; leaves linear-oblong_,
half-clasping, obtuse, _serrulate, crisped-wavy, 3-nerved; fruit
long-beaked_; upper portion of the embryo incurved in a large
circle.--Flowing and stagnant waters, Mass. to N. J. and Va., west to
western N. Y. June, July. (Eu.)
18. P. Mysticus, Morong. _Stem very slender_ and irregularly branching,
nearly filiform (1--3 deg. high); _leaves oblong-linear_ (1/2--11/2' long by
2--3'' wide), 5--7-nerved, _finely undulate and entire, obtuse or
bluntly pointed, abruptly narrowing at base, sessile or partly
clasping_; spikes few, capitate (4--6-flowered). on erect peduncles
(1--2' long); fruit (immature) obovate, small (hardly 3/4'' long),
_obscurely 3-keeled on the back_, a little beaked by the slender
recurved style.--Mystic Pond, Medford, Mass.
Sec. 3. _Leaves all submersed and similar, mostly membranaceous and
sessile, linear or setaceous._
[*] _Stipules free from the sheathing base of the leaf._
19. P. zosteraefolius, Schum. _Stem branching, wing-fattened; leaves_
linear and grass-like (commonly 4' by 11/2''), _abruptly pointed, with
many fine and 3 larger nerves_; stipules (seen young) oblong, very
obtuse; _spikes cylindrical_, 12--15-flowered, _not half as long as the
peduncle_; fruit obliquely obovate, somewhat keeled and with slight
teeth on the back, the sides not impressed, the face arching and
terminated by the short style; _summit of the large embryo lying
transverse to the fruit_. (P. compressus, _Fries_; not _L._?)--Still and
slow-flowing waters, N. Eng. to N. J., Iowa, and Minn. Aug., Sept. (Eu.)
20. P. Hillii, Morong. Stem slender, _widely branching, flattish_;
leaves linear, _acute_ (1--21/2' long by 1/2--11/4'' wide), _3-nerved_, the
lateral nerves delicate and near the margin; stipules whitish, striate,
obtuse (3--5'' long); _spikes capitate_ (3--6-fruited), _on short
spreading or recurved peduncles_; fruit as in the last.--Mich. and
western N. Y.
21. P. obtusifolius, Mertens & Koch. _Stem flattened, very branching;
leaves_ linear, tapering toward the base, obtuse and mucronate or very
acute, _3- (rarely 5-) nerved; stipules elongated_, very obtuse; _spike
ovate, continuous_, 5--8-flowered, _about the length of the peduncle_;
fruit oval, apiculate with the style, not keeled when fresh, _upper
portion of embryo_ coiled inward and _lying transverse to the
fruit_.--Slow streams and ponds, Canada and N. Eng. to western N. Y. and
Mich. Sept., Oct. (Eu.)
22. P. pauciflorus, Pursh. _Stem filiform, flattish and very branching;
leaves narrowly linear_ (1--2' long and seldom 1/2'' wide),
acute, _obscurely 3-nerved; stipules obtuse; spikes_ capitate,
1--4- _(usually 2-) flowered_, on short club-shaped peduncles; _fruit
roundish-lenticular_; the _back_ more or less _crested_; upper portion
of the embryo incurved in a circle.--Still or stagnant waters, N.
Brunswick to Ga., Iowa, Minn., and westward.
Var. Niagarensis, Gray. Stem often longer (1--3 deg.); leaves larger
(11/2--31/2' long by 1'' wide or less), 3--5-nerved at base, very acute and
mucronate, narrowed to the subpetiolate base. (P. Niagarensis,
_Tuckerm_.)--Running water, Great Lakes to S. C.; also in Cal.
23. P. pusillus, L. _Stem slender_, flattish or nearly cylindrical,
often very branching; _leaves narrow- or setaceous-linear_, acuminate,
_acute or subacute, 1--3-nerved_, furnished with _translucent glands_ on
each side at the base; stipules at first obtuse; spikes interrupted or
capitate, 2--8-flowered, on rather long peduncles; _fruit_ obliquely
elliptical, _scarcely keeled; apex of embryo_ incurved and _directed
obliquely downward_.--Pools and ditches, N. Scotia to N. J., west to
Minn. and Mo., and westward.--Leaves sometimes almost setaceous (var.
tenuissimus, _Koch_).
Var. polyphyllus, Morong. Dwarf form (3--5' high), divaricately
branching from the base, very leafy throughout; leaves very obtuse, not
cuspidate, 3-nerved; non-flowering but abundantly provided with
propagating buds which are formed on the thickened and hardened ends of
the branches and closely invested by imbricated leaves.--In a shallow
pool, S. Natick, Mass.
24. P. mucronatus, Schrad. Resembling P. pusillus, but stem less
branching; _leaves broader_ (almost 1'' wide), _often 5-nerved; spikes
interrupted_. (P. pusillus, var. major, _Fries_.)--N. Brunswick to
western N. Y., Mich., and Minn. July. (Eu.)
25. P. gemmiparus, Robbins. Stem filiform, branching, terete, varying
greatly in height; _leaves hair-like_, sometimes not as broad as the
stem, often with no apparent midrib, _tapering to the finest point_
(1--3' long), bi-glandular at base; stipules 1/2--1' long; spikes few
(3--6-flowered), _interrupted_, on long filiform peduncles; _propagating
buds very numerous_; fruit like that of P. pusillus, very rare. (P.
pusillus, var.? gemmiparus, _Robbins_.)--Slow-moving streams and still
water, Mass. Aug., Sept.
26. P. Tuckermani, Robbins. _Very slender and delicate_ from a creeping
rootstock, of a fine light green; stem filiform with several short and
repeatedly dichotomous leaf-bearing branches; _leaves_ thin and flat,
but _setaceous and tapering to near the fineness of a hair_ (1--4' long
and {1/3}'' extreme width), obscurely 1--3-nerved, with a few coarse
reticulations; stipules rather persistent below, {1/3}' long, obtuse;
_peduncle solitary, very long_, rather thickened upward; _spike
4--8-flowered, in fruit continuous, oblong; fruit thick-lenticular_,
obscurely 3-keeled; _nutlet slightly impressed on the sides; shell thick
and hard_; embryo nearly annular.--Cold ponds, White Mountains of N. H.,
N. Y., and N. J.
[*][*] _Stipules united with the sheathing base of the leaf._
27. P. pectinatus, L. _Stem filiform_, repeatedly dichotomous; _leaves
very narrowly linear_, attenuate to the apex, 1-nerved with a few
transverse veins; _spikes interrupted_, on long filiform peduncles;
fruit obliquely broad-obovate, compressed, _bluntly keeled_; shell of
nutlet very thick; _embryo spirally incurved_.--N. Brunswick to Fla.,
westward across the continent. Aug.--Oct. (Eu.)
28. P. marinus, L. Resembling narrow-leaved forms of the last species,
_low and very leafy_; peduncles much elongated; _fruit much smaller_
(1'' long) and thinner, round-obovate, _not keeled_ upon the rounded
back, tipped with the broad sessile stigma; _embryo annular_.--Western
N. Y., Ill., Mich., and southward. Probably the range of this species
is much more extensive than indicated, as it has been confounded with P.
pectinatus.
29. P. Robbinsii, Oakes. _Stem_ ascending from a creeping base, _rigid_,
very branching, _invested by the bases of the leaves and stipules;
leaves crowded in two ranks, recurved-spreading_, narrow-lanceolate or
linear (3--5' long and 2--3'' wide), acuminate, _ciliate-serrulate_ with
translucent teeth, many-nerved; stipules obtuse when young, their nerves
soon becoming bristles; _spikes numerous, loosely few-flowered_, on
short peduncles; fruit oblong-obovate (2'' long), _keeled with a
broadish wing_, acutely beaked; embryo stout, ovally annular.--In ponds
and slow streams, N. Brunswick to N. J., the N. shore of L. Superior,
and far westward.
4. RUPPIA, L. DITCH-GRASS.