ALTSMACEjE. 505 



MOl^OCOTYLEDONES. 



CXXV. ALISMACEiE. 



Flower-organs distinct from each other, or the carpids connected below. Seeds exalbu- 

 minous: embryo mostly cm'ved, with a large, usually slender radicle. — Aquatic or bog- 

 plants ; leaves rosular, mostly furnished with, a Made ; pedicels umbellate or whorled. 



1. ECHINODORUS, Uicl. 



Flowers hermaphrodite or polygamous. Sepals 3. Petals 3, imbricative. Stamens 

 usually definite, 6 or more. Achenia i-seeded, pluriserial on a convex torus, longitudinally 

 ribbed or crested. 

 /^ 1. E. cordifolius, Gt. Scape erect, Z-^-angalar, paniculate, with distant, herma- 

 phrodite whorls and umbels ; leaves emerging, cordate-roundish, 9-5-nerved, shorter than 

 the long petiole ; sepals many-ribbed, little shorter than the white petals ; stamens 12-15 ; 

 ovaries numerous, shorter than the style; carpids beaked: ribs about 13, entire. — Plum. 

 Ed. Burm. t. 234. f. 2. — Alisma, L. A. Berteroaum, Balb. A. Sprengelii, Ktk. ; young 

 specimens with oval or oblong, primoidal leaves. — 2'-4' high ; leaves 5"-3", petals 3^'" long, 

 carpid-beads 3'" diani. : beak at length half as long as the carpid.-^HAB. Jamaica !, Bancr., 

 ikfercA, in shallow ponds ; Antigua!, Wullschl. ; [French islands ! ; Guiana 1, Brazil !]. 



2. E. guianensis, Or. Scape simple, submersed, terminated by few-flowered umbels 

 or whorls ; leaves floating, hastate-oval, with the auricles somewhat pointed, much shorter 

 than the submersed petiole ; petals white, yellow at the base, little exceeding the many- 

 ribbed sepals ; stamens 6-12 ; styles shorter than the ovaries ; carpids bealcless : muricate 

 crests about 8, the dorsal larger. — Mart. Fl. Bras. 8. t. 13. /. 3 ; t. 15. /. 1.— Sagittaria, 

 Eth. S. echinocarpa, Jfori. (Alisma, &a5.). S. Seubertiana, if«r<. .- a form vrith rounded 

 leaf-auricles. — Leaves 2" long, smaller in a low, terrestrial form ; petals 6"'-9"' long, carpid- 

 heads 5"' diam. — Has. Trinidad!, &•., in savannahs; [Mexico to Brazil!]. 



2. SAGITTARIA, L. 



Character of Echinodorus, but flovfers unisexual, stamens usually indefinite, and achenia 

 flat, winged. —'Emerging water-plants ; primordial leaves devoid of a blade : in the sub- 

 sequent ones the blade is developed often by degrees ; flowers white, vMially moncecious, 

 the superior S ■ 



3. S. acutifolia, Z. Leaves sagittate, with the inferior veins recurved, (jfassing by 

 oval-oblong blades into the primordial ones) ; whorls distant : pedicels subequal ; stamens 

 numerous : filaments longer than the anthers ; carpids shortly mucronate, wholly sur- 

 rounded by a wing. — Desc. Fl. 7. t. 497. — Distinguished from the allied S. sagittifolia, L. 

 of the Old World by the fruit, and by longer filaments, and from S. obtusa, W. of the United 

 States by the nearly beakless caririds. — Hab. Jamaica!, all coll., in ditches; [Guiana!]. 



if 4. S. laucifolia, Z. Zeaves oval, tapering at the base, other oval-oblong or clliptical- 

 lanceolate: all veins ascending; whorls few-flowered, distant: superior pedicels shorter; 

 stamens numerous; anthers longer than the filaments; carpids mucronate . wing dorsal, 

 spongious.—Bot. Mag. t. 1792. Red. Zil. t. 411. Desc. Fl. 7. t. 498.— S. angustifolia, 

 Lindl. S. ovata. Bed. .- the form with the leaves quite developed.— Stouter than the pre- 

 cedmg; flowers large, but petals variable in size.— Hab. Jamaica!, Wils., Fd., M'Nab, in 

 ditches and lagoons ; [Cuba to Guiana !]. 



