The flower is constructed on the general monocotyledonous type, with 5
alternating, 3-merous whorls (Fig. 278), but exceptions are found as
in the Iridaceæ (Fig. 279) by the suppression of the _inner_ whorl of
stamens; in a few the position in relation to the bract differs from
that represented in Fig. 278, and in some instead of the trimerous,
di- or tetramerous flowers are found (_e.g. Majanthemum_, _Paris_).
Flowers generally _regular, hermaphrodite_, with simple, _petaloid_,
coloured perianth (except, for example, Bromeliaceæ); ovary trilocular,
generally with 2 ovules or 2 rows of ovules in the inner angle of
each loculus (Fig. 304 _C_, _D_). _Endosperm_ always present.--A very
natural family, of which some divisions in part overlap each other.
The habit varies; the leaves are however long, entire, with parallel
venation, except in Dioscoreaceæ (Fig. 313).
In the first orders of this family the flowers are hypogynous,
and in the first of all the styles are free, and the capsule
dehisces septicidally; in the following the flowers are
epigynous and in some reduced in number or unisexual; capsule
with loculicidal dehiscence, or a berry.
HYPOGYNOUS flowers: Colchicaceæ, Liliaceæ, Convallariaceæ,
Bromeliaceæ (in part).
EPIGYNOUS flowers: Amaryllidaceæ, Iridaceæ, Bromeliaceæ (in
part), Dioscoreaceæ.
Order 1. =Colchicaceæ.= The flower (Fig. 304 _A_) is ☿, regular,
_hypogynous_, trimerous in all five whorls (6 _stamens_); anthers
usually _extrorse_. Gynœceum with 3 _free styles_ (_A, D_); fruit a
_capsule with septicidal dehiscence_ (_E_); embryo very small (_F_).
The underground stem is generally a corm or rhizome, seldom a bulb.
=A.= VERATREÆ.--_Veratrum_; perennial herbs, stem tall with long
internodes and broad, folded leaves; the flowers andromonœcious,
with free, widely opening perianth-leaves (Fig. 304 _A_), and
globular anthers; inflorescence a panicle.--_Zygadenus, Melanthium,
Schœnocaulon, Uvularia, Tricyrtis_.
=B.= TOFIELDIEÆ.--_Narthecium_ and _Tofieldia_ have leaves alternate
(arranged in two rows), sword-like and borne in rosettes; racemes
or spikes. _Narthecium_ forms an exception to the order by having
a simple style and fruit with loculicidal dehiscence; _Tofieldia_
by the introrse anthers. In this they are related to the Liliaceæ.
_Narthecium_ has poisonous properties, like many other Colchicaceæ.
[Illustration: FIG. 304.--_Veratrum_: _A_ flower; _B_ stamen;
_C_ transverse section of ovary; _D_ gynœceum, with one carpel
bisected longitudinally, and the third removed; _E_ fruit after
dehiscence; _F_ longitudinal section of a seed.]
=C.= COLCHICEÆ.--_Colchicum_ (Autumn Crocus); perennial herbs, with a
long, _funnel-shaped, gamophyllous perianth_, and introrse anthers. The
flowers of _C. autumnale_ spring up immediately from the underground
stem, which is in reality a _corm_ formed of one internode. ~_Colchicum
autumnale_ flowers in autumn without leaves; in spring the radical
foliage-leaves appear simultaneously with the fruit. The flower is
protogynous, and is pollinated by insects (humble-bees, etc.) which
seek the honey secreted by the free part of the stamen a little way
down the tube. The length of the tube protects the fruit, and not,
as in other cases, the nectary.--_Bulbocodium_ and _Merendera_ have
unguiculate perianth-leaves, free, but closing together like a tube.~
175 species; chiefly in North America and South Africa.
_Tofieldia_ is an Arctic plant. The order is rich in pungent,
poisonous alkaloids (veratrin, colchicin, etc.). OFFICINAL;
the seeds of _Colchicum autumnale_ (Europe) and _Schœnocaulon
officinale_ (Mexico), and the rhizome of _Veratrum album_
(mountains of Central Europe).
[Illustration: FIG. 305.--_Colchicum autumnale. A_ Corm
seen from the front: _k_ corm; _s′ s″_ scale-leaves embracing
the flower-stalk; _wh_ base of flower-stalk with roots (_w_).
_B_ Longitudinal section of corm and flower-stalk: _hh_ brown
membrane surrounding the underground portion of the plant;
_st_ flower-and leaf-stalk of previous year, the swollen basal
portion forming the reservoir of reserve material. The new plant
is a lateral shoot from the base of the corm (_k_) and has the
following parts: the base bearing the roots (_w_), the central
part (_k’_) which becomes the corm in the next year, the axis
bearing the scale-leaves (_s’, s″_), the foliage-leaves (_l,
l′″_), and the flowers (_b, b’_) which are borne in the axils of
the uppermost foliage-leaves.]
Order 2. =Liliaceæ (Lilies).= Flowers as in the Colchicaceæ but with
_introrse_ anthers; _ovary free, 3-locular, with single style; capsule_
3-locular with _loculicidal_ dehiscence.--The majority are herbs with
_bulbs_; the inflorescence is _terminal_. In many species reproduction
takes place by means of bulbils (small bulbs) formed in the axils of
the foliage-leaves (_e.g. Lilium bulbiferum_, _lancifolium_, etc.,
_Gagea lancifolia_, etc.), or in the bracts of the inflorescence (many
species of _Allium_); in many species several buds are developed as
bulbs in the axils of the bulb-scales themselves (accessory buds
arising close together), and in some the formation of buds is common on
the leaves.
=A.= TULIPEÆ, TULIP GROUP. Bulbs. The aerial, elongated stem bears
the foliage-leaves. Flowers few but generally large, with free
perianth-leaves. _Tulipa_; style absent, no honey; flowers generally
solitary, erect.--_Fritillaria_ perianth campanulate with a round or
oblong nectary at the base of each perianth-leaf.--_Lilium_; perianth
widely open, generally turned back with a covered nectary-groove in the
centre of each segment. Anthers versatile.--_Lloydia; Erythronium._
=B.= HYACINTHEÆ, HYACINTH GROUP. Bulbs. Leaves radical; aerial stem
leafless with raceme or spike. In some the perianth-segments are free,
in others united. Honey is produced often in glands or in the septa of
the ovary (septal glands).--_Ornithogalum_ has a leafy stem; _Scilla_;
_Eucomis_ has a tuft of floral-leaves above the raceme; _Agraphis_;
_Hyacinthus_; _Puschkinia_; _Chionodoxa_; _Muscari_; _Veltheimia_;
_Urginea_.
=C.= ALLIEÆ, ONION GROUP. Generally bulbs. Leaves radical. Stem
leafless with a compound umbellate or capitate inflorescence of
unipared helicoid cymes, which before flowering are surrounded
by two broad involucral leaves.--~_Allium._ Filaments often
petaloid and bidentate; in many species bulbils are found in the
inflorescence.--Some species have flat leaves: _A. sativum_, Garlic;
_A. porrum_, Leek; _A. ursinum_; others have round, hollow leaves:
_A. cepa_, Onion; _A. fistulosum_, Winter Onion; _A. ascalonicum_,
Eschalot; _A. schænoprasum_, Chive.~--_Gagea_; honey is secreted
at the base of the perianth, no special nectary; inflorescence
few-flowered.--_Agapanthus; Triteleia._
=D.= ANTHERICEÆ. Rhizome; raceme; the leaves not fleshy and
thick.--_Anthericum_; _Asphodelus_; _Bulbine_; _Chlorophytum_;
_Bowiea_ has an almost leafless stem with curved, climbing
branches.
=E.= ALOINEÆ, ALOES. Stem generally aerial and tree-like,
bearing on its summit thick, fleshy leaves, often with a thorny
edge (Fig. 306). Raceme branched or unbranched.--_Aloë_;
_Gasteria_; _Yucca_ (has secondary thickening, p. 274).
=F.= HEMEROCALLIDEÆ. _Phormium_, (_Ph. tenax._ New Zealand
Flax); _Funckia_ (_Hosta_); _Hemerocallis_.
At this point the following are best placed: _Aphyllanthes_
(_A. monspeliensis_); _Xanthorrhæa_ (Black-boy); _Xerotes_;
_Lomandra_; _Kingia_; the very membranous, dry perianth of the
last resembles that of the Juncaceæ, and also there are only
1–few ovules in the loculi.
POLLINATION by insects. Honey in some is produced on the
perianth (see Tulipeæ), in others by glands on the carpels (in
the septa and parietal placentæ, septal glands): _Hyacinthus_,
_Allium_, _Anthericum_, _Asphodelus_, _Yucca_, _Funckia_,
_Hemerocallis_, etc. Some _Allium_-species are protandrous.
_Fritillaria_ is visited by bees, _Lilium martagon_ by moths,
_L. bulbiferum_ by butterflies, _Phormium_ (New Zealand) by
honey-birds.
[Illustration: FIG. 306.--Aloë.]
About 1,580 species; rare in cold climates; their home is in
sunny plains with firm, hard soil, and warm or mild climate,
particularly in the Old World (S. Africa; As. Steppes;
Mediterranean); at the commencement of spring the flowers
appear in great profusion, and after the course of a few weeks
disappear; during the hot season their life lies dormant in the
bulb, hidden underground. The woody species are tropical.--The
majority of the _introduced_ Liliaceæ (_Fritillaria imperialis_,
Crown-imperial; _Lilium candidum_; _Tulipa gesneriana_;
Hyacinth; _Muscari_-species; _Scilla_-species; _Ornithogalum
nutans_; _Hemerocallis fulva_ and _flava_; _Asphodelus luteus_
and _albus_) come from the Mediterranean and W. Asia; _Funckia_
from China and Japan; several Lilies from Japan and the
Himalayas; _Agapanthus_ from the Cape; _Allium sativum_ is a
native of the Kerghis-Steppes; _A. cepa_ from Persia (?); _A.
ascalonicum_ is not known wild (according to others a native of
Asia Minor), perhaps a form of _A. cepa_; _A. schænoprasum_ from
the N. temp. region.
Many bulbs have pungent properties; many Onions are used as
culinary plants. The bast fibres of _Phormium tenax_ (New
Zealand Flax) are used technically. Dyes are obtained from the
_Aloe_; gum for varnish from the stem of _Xanthorrhæa hostile_
and _australe_. OFFICINAL; “Aloes,” the dried sap of S. African
species of _Aloe_ (_A. Africana_, _A. ferox_, etc.); the
bulb known as “Squills” from _Urginea_ (_Scilla_) _maritima_
(Mediterranean).
Order 3. =Convallariaceæ.= This order differs from the Liliaceæ in
having the _fruit a berry_ (Fig. 308) and _in never being bulbous_; the
seeds are less numerous.
=A.= CONVALLARIEÆ, LILY OF THE VALLEY GROUP. Rhizome (Fig. 307) and
normal foliage-leaves.--_Polygonatum_: rhizome creeping; aerial
shoot leafy, bearing the flowers in racemes in the axils of the
foliage-leaves; perianth tubular. _P. multiflorum_ (Solomon’s seal),
_P. officinale_, etc.--_Majanthemum_: flower 2-merous; perianth
almost polyphyllous, spreading. _Smilacina. Streptopus_ (_S.
amplexifolius_; the flowers or inflorescence unite with the entire
succeeding internode).--_Convallaria_ (1 species _C. majalis_, Lily
of the valley); flowers in terminal racemes; 2 basal foliage-leaves;
perianth globose, bell-shaped. _Reineckea carnea_ (Japan, China) in
gardens.--_Paris_ (_P. quadrifolia_, Herb-Paris); flowers solitary,
terminal, 4-merous, polyphyllous; styles 4, free (approaching the
Colchicaceæ; it is also poisonous); a whorl of 4 (-more) 3-nerved,
reticulate leaves on each shoot.--Ornamental plants: species of
_Trillium_, _Aspidistra elatior_ (Japan).
[Illustration: FIG. 307.--Rhizome of _Polygonatum multiflorum_:
_a_ bud; _b_ shoot; _c d_ scars left by shoots of previous
years.]
[Illustration: FIG. 308.--_Smilax pseudosyphilitica_: _A_ shoot
of male plant; _C_ ♂-flower; _D_ berry, almost ripe; _E_ the same
in longitudinal section. _B Smilax syphilitica_: portion of
branch with base of leaf and tendrils.]
=B.= ASPARAGEÆ, ASPARAGUS GROUP. Scale-like leaves and green
assimilating branches.--_Asparagus_: horizontal rhizome. The aerial
shoots are very richly branched; the numerous needle-like bodies upon
the plant are _leafless shoots_, which are crowded together in double
scorpioid cymes in the axils of the scale-leaves; the two first lateral
axes, placed outside to the left and right, generally bear flowers.
Polygamous.--~_Ruscus_ (Butcher’s broom) is a S. European _shrub_ with
_leaf-like_, ovoid or elliptical shoots (phylloclades) which are borne
in the axils of scale-like leaves, and bear flowers on the central
line. Diœcious. Stamens 3, united, anthers extrorse. _Semele androgyna_
bears its flowers on the edge of the flat shoot.~
=C.= SMILACEÆ. _Smilax_ (Sarsaparilla) (Fig. 308); _climbing_
shrubs with the leaf-sheath produced into tendrils. The leaves have
3–5 strong nerves proceeding from the base, and are reticulate.
Orthotropous or semi-anatropous ovules. Diœcious (Fig. 308 _C_, _E_).
=D.= DRACÆNEÆ. Fruit in some a berry, in others a capsule.
The stem of DRACÆNA, when old, has the appearance of being
dichotomously branched; it has the power of increase in
thickness, and may become enormously thick. The Dragon-tree of
Teneriffe, measured by Humboldt, attained a circumference of
14 m. and a height of 22 m.; the leaves are large, linear or
linear-lanceolate.--_Cordyline_ (East Asia), various species in
gardens and greenhouses (_Yucca_ is closely allied). _Astelia._
POLLINATION. _Paris quadrifolia_ and _Convallaria majalis_
have no honey, and are chiefly visited by pollen-collecting
bees (in the absence of insect visits self-pollination takes
place); _Polygonatum multiflorum_ has honey secreted by septal
glands and protected by the base of the tubular perianth; it
is pollinated by humble-bees, etc. _Asparagus officinalis_ has
small, polygamous, greenish, honey-bearing flowers; the ♂-flower
is almost twice as large as the ♀; both have rudiments of the
opposite sex.
About 555 species; especially from N. America, Europe, and
Central Asia.
OFFICINAL: “Dragons’-blood,” a red resinous juice from the stem
of _Dracæna_ and the roots of some Central American species of
_Smilax_. The tuberous stems of the Eastern Asiatic _Smilax
glabra_ are officinal. The flowers of _Convallaria majalis_
have been lately used as a substitute for _Digitalis_. Pungent,
poisonous properties are possessed by _Paris_. None of the
species are used as food, except the young annual shoots of
_Asparagus officinalis_, a shore-plant which is used as a
vegetable.
Order 4. =Pontederiaceæ.= Flowers generally zygomorphic,
hypogynous, ☿, with handsome, white or violet, petaloid perianth
which forms a tube at its base. The stamens are inserted at
different heights in the perianth-tube, and are reduced to
three (in _Heteranthera_ seldom to one). In some the ovary is
trilocular with ∞ ovules (_Eichhornia_), in others reduced to
one loculus with one ovule (_Pontederia_). Fruit a capsule or
nut. Embryo as long as the abundant, mealy endosperm.--Tropical
water-plants (22 species) with peculiar sympodial branching,
nearly the same as in _Zostera_. Spikes without floral-leaves.
Many intercellular spaces in the stem and leaf.--In greenhouses:
_Eichhornia azurea_, _E. crassipes_ (both from tropical and
sub-tropical S. America); the latter has swollen petioles which
serve as floats and enable it to float freely on the water,
sending down its roots into the mud. _Heteranthera reniformis,
H. zosterifolia. Pontederia cordata._
Order 5. =Amaryllidaceæ (Narcissi).= The flower is _epigynous_,
otherwise exactly the same as in the Liliaceæ (6 stamens). The
majority, like these, are also _perennial_ herbs with bulbs and scapes.
The fruit and the other characters as in the Liliaceæ. The external
appearance is, however, very different.
=A.= AMARYLLEÆ have bulbs and the leaves generally arranged in two
rows; the flowers are borne singly or in umbel-like inflorescences
on lateral scapes, while the main axis of the bulb is unlimited.
Beneath the inflorescence is an _involucre_ (Fig. 309).--_Galanthus_,
Snowdrop, has a polyphyllous perianth without corona; the three inner
perianth-leaves are emarginate and shorter than the outer; the anthers
dehisce apically. ~_Leucojum_ differs in having the perianth-leaves
equal in length.--_Amaryllis_ has a funnel-shaped perianth, entirely
or nearly polyphyllous, but somewhat zygomorphic. _Crinum; Hæmanthus;
Clivia._~--_Narcissus_ has a tubular _corona_, a ligular structure
arising from the perianth-tube exterior to the outer stamens. ~In
_Pancratium_ (Fig. 309) the corona is united with the filaments which
appear to spring from its edge. _Eucharis amazonica._~
[Illustration: FIG. 309.--_Pancratium caribæum._]
=B.= HYPOXIDEÆ. The leaves, which are grass-like, dry, folded,
and in some hairy, spring from a rhizome, generally with a
divergence of 1/3. Flowers small, perianth polyphyllous,
persistent, on which account perhaps the Hypoxideæ may be
considered as the least altered type. The chief characteristic
is that the embryo is separated from the hilum. _Hypoxis_;
_Curculigo_ (_C. recurvata_, a favourite ornamental plant; S.E.
Asia).
=C.= ALSTRŒMERIEÆ. (_Alstrœmeria_, _Bomarea_); stems long,
leafy, often climbing.
=D.= VELLOSIEÆ (_Vellosia_, _Barbacenia_); stem woody, usually
dichotomously branched, with terminal, single flowers; it bears
numerous aerial roots which pierce the leaves and surround the
stem. Stamens often (by splitting) 6–18. High table-lands of S.
America and S. Africa.
=E.= AGAVEÆ. Very similar to the Bromeliaceæ both in their
distribution (nearly all American) and in external appearance.
They appear as gigantic bulbous plants with perennial, aerial,
generally short stem, and perennial, large, lanceolate or
linear, stiff, thick, and often thorny leaves, which form a
large rosette; after the course of several (8–20) years the
terminal inflorescence is developed, which is 10–12 m. high,
paniculate, and freely branched. Before the inflorescence
expands, a large quantity of sugar-containing sap is collected
from _A. americana_ by removing the terminal bud; this on
distillation yields “pulque,” the national drink of Mexico.
After flowering the entire shoot dies, but the subterranean
lateral shoots survive and reproduce the plant.--_Agave
americana_, etc.; _Fourcroya_; _Polianthes tuberosa_ (Tuberose;
Central America).
DISTRIBUTION. The 650 species are chiefly natives of S. Africa
and S. America. _Clivia_, _Hæmanthus_, _Amaryllis_ are from the
Cape; _Narcissus_ from S. Europe, whence many species have been
introduced; _Galanthus_ and _Leucojum_ are especially from S.
and Central Europe, and from the Caucasus.
USES, few, except as ornamental plants: _Galanthus nivalis_;
_Leucojum_; _Narcissus pseudonarcissus_, _N. poeticus_, _N.
jonquilla_, _N. tazetta_, etc.; _Amaryllis_, _Alstrœmeria_,
_Eucharis_, _Crinum_, _Vallota_, etc. The vascular bundles of
the various species of _Agave_ (_Agave rigida_, var. _sisalana_,
sisal hemp,) are used for cordage, etc.
Order 6. =Bromeliaceæ.= The flowers are hypogynous, epigynous or
semi-epigynous; the perianth is divided into _calyx_ and _corolla_;
stamens 6. The fruit is a capsule or berry with many seeds. Endosperm
_mealy_, embryo small, at the edge of the endosperm, but not enclosed
by it.
[Illustration: FIG. 310.--_Aechmea miniata._]
[Illustration: FIG. 311.--Multiple-fruit of _Ananassa sativa_.]
Perennial herbs with a very _characteristic appearance_ (Fig. 310);
the stem is most often short, thick, and crowned by a _rosette_ of
many leaves, which are long, often very narrow, _leathery_, stiff, and
with a _spiny_ edge; they are usually channeled, completely closing
round each other, with their edges forming a tightly closed hollow, in
which generally water is collected (this among other things insulates
the inflorescence and thus prevents the access of creeping insects,
such as ants). The presence of numerous stellate, water-containing
hairs often gives the leaves a grey appearance, and the layers of
cells beneath the upper epidermis of the lamina form an “aqueous
tissue,” which serves as a protection against the rays of the sun and
regulates the evaporation. The stomata are often situated in furrows
on the underside of the leaf, and hence cause a striped appearance.
They _are all American_ (525 species), especially from S. America,
where they live partly as epiphytes _on trees_, partly in the _clefts
of rocks_, often on the steepest slopes, to which they firmly attach
themselves by aerial roots; some are terrestrial. The stem is seldom
tree-like or many metres in height (_Puya_, in Chili; _Hechtia_, in
Mexico). _The inflorescence_ is a terminal spike, raceme, or panicle,
often with large and brightly-coloured floral-leaves. The flowers are
without scent. The seeds, in the species whose fruit is a capsule,
are often provided with wings (hairs, expansions, etc).--_Ananassa
sativa_, Pine-apple (W. Indies, Central America) is cultivated for the
sake of its juicy, aromatic fruits, which coalesce with their fleshy
bracts and form a large spike-like fruit-cluster (multiple-fruits,[29]
Fig. 311) bearing on its apex a leafy shoot, which may be used as a
cutting. Seeds very rarely developed.--_Tillandsia_ (_T. usneoides_ is
a filamentous, richly branched, rootless epiphyte hanging in masses
from trees; Trop. Am.), _Aechmea_, _Billbergia_, _Pitcairnia_, etc.
USES. The leaves of the Pine-apple, in its native country, are
used for the manufacture of cloth.
Order 7. =Hæmodoraceæ.= 120 species; in all parts of the world
except Europe; perennial, often tomentose and resembling
the Bromeliaceæ, Iridaceæ and Amaryllidaceæ. _Hæmodorum_
(Australia).--To this order belong _Ophiopogon_, _Peliosanthes_,
_Sanseviera_, and others.
Order 8. The =Iridaceæ= have _epigynous_, hermaphrodite flowers with
petaloid perianth as in the Amaryllidaceæ, but the _interior whorl of
stamens is entirely suppressed_, and the 3 developed _outer_ stamens
have _extrorse_ anthers (Fig. 279); there is 1 style with 3 large,
generally _more or less leaf-like branches bearing the stigmas_.
Ovary and capsule as in the Amaryllidaceæ and Liliaceæ.--Perennial
herbs; _bulbs are rarely found_, but horizontal rhizomes, corms, etc.,
take their place. The leaves are (except _Crocus_) as in the _Iris_,
_two-rowed_, _equitant_ and _sword-like_. Flowers or inflorescences
terminal.
The _Iris_ (Flag) has a horizontal rhizome. The flowers are borne in
the leaf-axils in fan-like inflorescences (rhipidium). The branches of
the style are large and _petaloid_; on their under surface may be seen
a small projecting shelf (Fig. 312 _a_) having on its upper surface the
stigmatic hairs. Beneath the branches of the style are 3 well protected
stamens, and immediately outside these the external perianth-leaves.
~The honey is secreted in the perianth-tube, and the insects,
endeavouring to obtain it through the narrow passages at the base of
the stamens, settle upon the outer perianth-leaves, which are bent
backwards and often very hairy along their central line. The insects
then rub their backs on the anthers just above them, beneath the
branches of the style; they readily deposit the pollen on the stigma
of another flower as they enter it, but cannot do so in withdrawing,
since the stigma is pushed back, and self-fertilisation is thus
avoided. The stylar branches lie close to the outer perianth-leaves,
which are just beneath them, or separated by a distance of only 6–10
mm.; the first form of flower is adapted for _Rhingia rostrata_, the
latter for bees~.--_Crocus_ has vertical, _tuberous_, underground stems
surrounded by the leaf-sheaths (corms), and terminal flowers; the
linear leaves _are not equitant_, but have two longitudinal furrows
on the under side. The perianth is gamophyllous and funnel-shaped.
The stylar branches (stigmas) are fleshy, _rolled together in the
shape of a horn_, and split along the edge.--_Gladiolus_ has corms
like the _Crocus_; spikes with slightly zygomorphic, almost bilabiate
flowers, most frequently turning to one side. Position of the leaves
as in the Iris.--~_Diplarrhena_ has 2 fertile and 1 barren stamen;
_Hermodactylus_ has a unilocular ovary with 3 parietal placentæ.
_Cypella_ and _Tigridia_ have bulbs.~
[Illustration: FIG. 312.--_Iris pseudacorus._ One external and
two internal perianth-leaves, and one of the stylar-branches
have been removed, _y_ The outer, _i_ the inner perianth-leaves;
_g_ stylar-branch; _a_ stigma; _s_ anther. The ovary is seen in
longitudinal section.]
770 species; chiefly in the countries round the Mediterranean,
and in Africa, especially the Cape (_Gladiolus_, _Ferraria_,
_Moræa_, _Galaxia_, _Sparaxis_, _Antholyza_, _Tritonia_,
_Ixia_, etc.), Australia and Tropical America (_Sisyrinchium_,
_Tigridia_, _Cipura_, _Cypella_, etc). A great number are
ornamental plants: the cultivated _Crocus_-species are from the
South of Europe and Asia; _Gladiolus communis_ from S. Europe;
the other species principally from S. Africa. The native species
of _Iris_ are _I. pseudacorus_ (yellow) and _I. fœtidissima_.
OFFICINAL: the stigmas of _Crocus sativus_ (Oriental, cultivated
in France, Spain, Italy, and Austria), used as a colouring
matter, saffron; the rhizomes of the S. European _Iris
florentina_, _pallida_, and _germanica_ (“Orris-root”).
[Illustration: FIG. 313.--_Dioscorea batatas_: _A_ ♂-plant; _B_
♂-flower; _C_ ♀-plant (nat. size); _D_, _E_ ♀-flowers (mag.); _F_
seed; _G_ embryo.]
Order 9. =Dioscoreaceæ.= Perennial herbs with fleshy, often very large
_tuberous rhizomes_ (or roots); _twining_ stems; leaves stalked, often
arrow- or heart-shaped, lobed, _palminerved_ and _finely reticulate_
as in the Dicotyledons (Fig. 313). The flower is _diclinous_ (most
frequently _diœcious_), regular, _epigynous_, _small_, and of a
_greenish colour_, but otherwise typical (Pr3 + 3, and A3 + 3, or G3);
in most instances 2 ovules are placed one above the other in each
loculus. The inflorescence is a _spike_ or _raceme_, sometimes richly
branched and paniculate.--The order approaches most nearly to the
Amaryllidaceæ.
_Tamus_ (Bryony) has a berry, _Dioscorea_ (Yam) a thin-walled, 3-edged
or 3-winged capsule (Fig. 313). Both have subterranean or aerial
tubers; the Yam very often also developes tubers in the axils of the
foliage-leaves; tuberous roots are said to occur in _D. batatas_.
The tubers of many species of Yams (_D. batatas_ from China and
Japan, _D. alata_, South Sea Islands and India, _D. bulbifera_) are
a very important source of food in the Tropics, especially the
first-named.--_Testudinaria_; _Rajania_.--~The tuberous stem of
_Tamus communis_ and _Testudinaria elephantipes_, and some species
of _Dioscorea_ is formed from one single internode (epicotyl), and
the aerial shoots are developed from adventitious buds; in _T.
elephantipes_ the stem is aerial, and covered with thick scales of
cork, regularly arranged, and separated by grooves.~
Tropical order (167 species); 2 species (_Tamus communis_ and
_Borderea pyrenaica_) in Europe.