ALISMACE. 69 
bulbs at their extremity, and from which new plants are developed. 
Early leaves all submerged or floating on the surface of the water, 
resembling the floating leaves of Sparganium simplex, but broader 
towards the apex, and having several ribs with lax areolation between 
them; later leaves rising out of the water, triangular, with 2 long acute 
basal lobes pointing backwards, commonly nearly as long as the rest of 
the lamina, which as well as the basal lobes has several ribs connected by 
eross veins. Scape at length rather longer than the leaves, with distant 
whorls with membranous bracts at the base; 1 or 2 of the lowest 
whorls consist of female flowers on peduncles rarely more than + inch 
long even in fruit; the two or three uppermost whorls of male flowers 
on peduncles } to 1} inch long while the flowers are expanded. Flowers 
3 (or 4) ina whorl. Female flowers about } inch across, the male ? 
inch, both with the inner perianth leaves diaphanous, pure white with 
a purple base, deciduous. Anthers dark purple. Fruit in heads $ to ¢ 
inch in diameter, half-obovate-semicircular, flattened, thin, olive, with 
an apiculus forming a continuation of the upper margin, the greater 
portion consisting of a corky wing; seed-bearing portion oblong. 
Plant bright green, glabrous, very variable in the shape and size of 
the leaves and height of the scapes according to the depth of the 
water in which it grows; the former 2 inches to 1 foot long, including 
the basal lobes, the latter 4 inches to 2 feet 6 inches. 
Common Arrowhead. 
French, Sagittaire fléche d’cau. German, Gemeines Pfeilkraut. 
This is a plant of remarkable beauty, and affords the finest example in nature of 
the arrowheaded leaf. Its roots contain an amylaceous matter, which is said to form 
a nutritious food, and is eaten by the Chinese and Kalmuk Tartars. 
GENUS IV.—ALISMA. Lino. 
Flowers perfect. Perianth with the 3 outer leaves herbaccous, sub- 
| persistent ; 3 inner leaves larger, petaloid, caducuous. Stamens 6, 
| hypogynous ; filaments filiform ; anthers introrse, affixed by the back. 
Ovaries very numerous, free, 1-celled and 1-ovuled; stigma simple. 
Fruit of numerous verticillate or subcapitate achenes. 
Marsh herbs with a cormose rhizome and radical stalked leaves with 
-cancellate venation, rounded, cordate or wedgeshaped at the base, 
sometimes with the lamina absent: occasionally the scapes root and 
_ produce leaves at the nodes. Flowers white or pale lilac, in a panicle 
on a scape with verticillate branches or pedicels. 
The derivation of the name of this plant is said to be from the Celtic alis, water, 
where the species grow. 
