536 ALISMA. I^CI-ASS VI. OUDER V. 



stalk, dilated below wiib a pale ibin membranous margin. IScape 

 erect, from four to six inches bigb 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 hracteas. Flowers 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'ce^. R. Brown. 



Gen. Char. CaZya; of three pieces. Pe^a?* three. OmWe* numerous. 

 Nuts distinct, numei'ous, 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. Scape 

 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. 



jS, lanceolatum. Leaves lanceolate, tapering at the base. 



A. Zaweeo^a^a, Withering. — A. Plantago, var. /5. Willd. and Smith. — 

 English Flora, vol. ii. p. 203. 



y. graminifolium. Leaves linear, floating. 



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

 Ehrh. her]). — A, Plantago^ var. y. Smith. — English Flora, vol. ii. 

 p. 203. 



