432 THE ALISMA FAMILY. 
Ill. ALISMA. WATER PLANTAIN. 
Aquatic herbs, erect or rarely floating, with radical, long-stalked 
leaves ; the flowers either in a terminal umbel, with or without whorls — 
of pedicellate flowers below it, or in a panicle with whorled branches 
each bearing a similar umbel. Perianth of 3 outer, small, herbaceous 
segments, and 3 much larger inner ones, petal-like; and very delicate. 
Stamens 6. Carpels numerous, small, and 1-seeded, either arranged in 
a ring round the axis, or irregularly in a globular head. 
A genus comprising several species, chiefly American, but some of 
them distributed over nearly the whole world. 
Flowers numerous, in a loose panicle. Carpels forming a ring = 
round the axis of the flower . ‘ : 3 . : . lL. A. Plantago. 
Flowers few, inasingle umbel. Carpels irregularly arranged . 
in a globular head. 
ae ae or creeping. Carpels with 4 or 5 ii 5: 
é . 2. A. ranunculoides. 
Stems ating. Carpels with 12 to 15 slender ribs . : . 3& A. natans. 
1. A. Plantago, Linn. (fig. 974). Common W.—Rootstock perennial, 
becoming almost bulbous by the thickened sheathing bases of the leaf- 
stalks. Leaves radical, varying from ovate to narrow-lanceolate. 
Flower-stem 1 to 3 feet high, with whorled branches, unequal in length, 
forming a loose, pyramidal panicle. Flowers rather small, of a pale 
rose-colour, ‘on long whorled pedicels. Fruit of 20 to 39 carpels, 
arranged in a single ring round a broad, flat, central axis. 
In watery ditches, ponds, and edges of streams ; common in Europe, 
temperate Asia, and North America, extending to the Arctic regions, 
and reappearing in Australia. Abundantin Britain. FV. all summer. 
2. A. ranunculoides, Linn. (fig. 975). Lesser W.—The leaves and 
peduncles form annual tufts, but will occasionally emit runners for a 
succeeding year. Leaves narrow-lanceolate, or sometimes reduced to 
a linear leafstalk. Flower-stems, in the ordinary state, simple, with a 
single terminal umbel, or rarely a second whorl below it. Flowers 
larger than in A. Plantago, sometimes near an inch diameter. Carpels 
irregularly arranged in a globular head in the centre of the flower. 
In wet ditches and marshes, over the greater part of Europe, but 
rare in the east. In Britain, as widely dispersed as A. Plantago, but 
not near so frequent. Fl. summer and autumn. In var. repens the 
flowering-stem bends down, and forms roots and leafy tufts at each 
whorl of flowers. 
3. A. natans, Linn. (fig. 976). Floating W.—Stems slender, and 
floating on the surface of the water, producing at every node a tuft of 
small ovate or oblong, stalked leaves, and 1 or 3 small flowers, whilst 
the radical leaves of the original tuft are all reduced to a linear leaf- 
stalk, scarcely dilated towards the top. Carpels in a globular head, 
like those of A. ranunculoides, but much more pointed, and marked with - 
12 to 15 slender longitudinal ribs. 
In ponds and still waters, in western and some parts of central Europe. 
In Britain very rare, and confined to western England, Wales, and west- 
ern Ireland. [The subsolitary flowers, floating habit, and position of the — 
ovules, separate this from Alisma, under the name of Elisma, Buchenau. ] : 
Fl, summer and autumn. 
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