536 ALISMA. tCLASS VI. ORDER V. 



Stalk, dilated below with a pale thin membranous margin. Scape 

 erect, from four to six inches high or more, round, smooth, simple, 

 bearing two, sometimes three sessile umbels, one above another ; pedun- 

 cles about six in number, simple, single-flowered, surrounded at the 

 base with two or three membranous ovate bracteas. Floivers white, 

 yellow at the bottom. Calyx of three ovate concave pieces, persistent, 

 green. Petals three, roundish, with a short claw, longer than the 

 calyx. Stamens with awl-shaped filaments, shorter than the petals, 

 and roundish two-celled yellow anthers. Capsules six, compressed, 

 narrow pointed, keeled, united at the base, and spreading in a star-like 

 manner, bursting longitudinally, each containing two seeds " upon 

 evident stalks, one from the upper angle horizontal, the other from the 

 lower angle of the axis, erect, oblong, tuberculated and transversely 

 striated, compressed, with a deep furrow on each side, occasioned by 

 the form of the embryo within, which is cylindrical, and bent double 

 somewhat like a horse-shoe." — Hooker. 



Habitat. — Ditches and pools, especially in a gravelly soil in the 

 middle and south-eastern counties of England. 



Perennial ; flowering in June and July. 



ORDER V. 



POLYGYN'IA. Many Pistils. 



GENUS XXIX. ALIS'MA.— Linn. Water Plantain. 



Nat. Ord. ALisMA'cEiE. R. Brown. 



Gen. Char. Ca??/a; of three pieces. Pe<fl?s three. Omn'e* numerous, 

 Nuts distinct, numerous, clustered, indehiscent, single-seeded, 

 deciduous. — Name from alis, water in Celtic, all the species of 

 this genus growing in water. 



1. A. Planta'go, Linn. (Fig. 612.) Greater Water Plantain. Scapfe 

 terminating in whorled panicles; leaves all radical, ovate, acute; 

 carpels obtusely triangular, numerous, in a roundish flat head. 



English Botany, t. 837.— English Flora, vol. ii. p. 203.— Hooker, 

 British Flora, vol. i. p. 175. — Lindley, Synopsis, p. 253. 



/3. lanceolatum. Leaves lanceolate, tapering at the base. 



A. ZanceoZaia, Withering. — A. Plantago, var. /3. Willd. and Smith. — 

 English Flora, vol. ii. p. 203, 



y. graminifolium. Leaves linear, floating. 



A. Plantago, y^ graminifolium, Wahlenb. suec. — A. graminifolium 

 Ehrh. herb. — A. Plantago, var. y. Smith. — English Flora, vol. ii. 

 p. 203. 



