Alisma. ] LXXIX. ALISMACER. 431 
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 leafstalk, 
scarcely dilated towards the top. Carpels in a globular head, like those or 4. 
rancuunloides, 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 Hlisma, Buchenau, ] 
Fl. summer and autumn. 
- IV. DAMASONIUM. DAMASONIUM. 
Herbs, only differing from Alisma in the carpels, which are few, larger, 
usually 2-seeded, and cohere by the base to the central axis of the flower. 
Besides the European species, the genus comprises two others from 
Australia and California. . 
1, D.stellatum, Pers. (fig. 972). Star Damasonium.—A tufted, 
glabrous annual. Leaves all radical, on long stalks, ovate or oblong, often 
cordate at the base. Flower-stems erect, from 3 to 9 inches high, usually 
bearing 1 terminal umbel, and 1 to 3 whorls of rather small flowers lower 
down. Inner segments of the perianth very delicate, white, with a yellow 
spot at the base. Carpels 6, tapering into a long point, and radiating 
horizontally, like a star. Actinocarpus, Damasonium, Br. 
In watery ditches, and pools, in western and southern Europe, and west- 
central Asia, but not extending into Germany or Scandinavia. In Britain, 
only in some of the southern and eastern counties of England. 7. summer. 
oe 
V. SCHEUCHZERIA. SCHEUCHZERIA. 
_ Erect marsh plant with few linear leaves, and a short, loose terminal 
raceme. Perianth-segments 6, small and equal, with an anther sessile at 
the base of each one. Carpels 3 to 6, each containing 1 or 2 seeds, and 
opening inwards by longitudinal slits. . 
The genus is limited to the single British species, nearly related to 
Triglochin, and with it forming the distinct tribe of Juncaginee, by some 
regarded as a separate family, and which in the ‘ Flora Australiensis” I 
have proposed to connect with Potamogeton as a tribe of Navadee. 
As this change has not yet been sanctioned by botanists in general, I 
have been unwilling to disturb the arrangement followed in previous 
editions. | 
1. S. palustris, Linn. (fig. 973). Marsh Scheuchzeria.—A. rush-like 
perennial, with a creeping rootstock, and an erect stem about a foot high, 
Leaves few, linear, sheathing at the base, then narrowed, and nearly cylin- 
drical ; the lower ones often longer than the stem; the upper ones passing 
into short, sheathing floral bracts. Flowers few, rather small, on pedicels 
about 6 lines long, forming a short, loose terminal raceme. Perianth 
slightly coloured, of 6 spreading or reflexed segments. Stamens6. Carpels 
3, rarely 4 to 6, nearly 3 lines diameter when ripe, opening by a longitu- 
dinal slit, and containing 1 or 2 seeds. 
