84 



ALISMACEAE (WATEE PLANTAIN FAMILY) 



** Species of the interior; leaf-blades relatively large, sagittate with broad 

 triangular auricles. 



2. L. calycinus (Engelm.) J. G. Sm. Taller (1.5-4 dm. high) ; leaf-blades 

 deeply sagittate, thin, 10-15-nerved, 4-8 era. broad, the auricles triangular, 

 acute, nearly or quite as long as the terminal portion of the blade ; stipes re- 

 curving or procambent, 1-4 dm. long, usually bearing 3-4 whorls of flowers ; 

 Head of carpels about 1 cm. in diameter. {Sagittaria Engelm.) — ^ Muddy banks, 

 Mich, to Dali. and southw. 



Var. miximus (Engelm.) Kobinson. Leaf-blades very large (3 dm. wide), 

 18-21-nerved, considerably broader than long, the auricles almost divaricate ; 

 Inflorescence stout, sometimes branched. {Sagittaria calycina, var. Engelm. \ 

 — 0. {Moaeley) and southw. 



42. E. tenellus. 



a, FI. X 1. b. Ft. x 1, 



c. Acliene 8. 



3. ECHIN6dORUS Richard. 



Petals imbricated in the bud. Stamens 6-21 or more. — Mostly annuals, with 

 the habit of Sagittaria, the naked stems sparingly branched or simple, and the 

 flowers on rather short pedicels, in Avhorls of 8-6 or more. 

 Fl. summer and autumn. (Name from ixi-vdi-os, prickly, 

 or from ix^voi, and 5op6s, a leathern bottle, applied to the 

 ovary, which is in most species armed with the persistent 

 style, so as to form a sort of prickly head of fruit. ) 

 l/'l. E. tenellus (Martins) Buchenau. Scapes 1.5-10 em. 

 high ; shoots often creeping and proliferous ; submersed 

 leaves lance-linear phyllodia, emersed leaves petiolate with 

 a lanceolate blade, acute (1-3 cm. long) ; umbel single, 

 2-8-flowered ; pedicels reflexed in fruit ; flower 6 mm. 

 broarl ; stamens 9 ; styles much shorter than the ovary ; 

 achenes beakless, 8-ribbed, reddish brown, without glands. 

 (Alisma Martins ; Helianthium Britton ; E. 

 Engelm.) — Submersed or on mud, e. Mass., Mich., Minn., and 

 southw. (S. A.) Fig. 42. 



2. E. cordifblius (L.) Griseb. Scape erect, 1-6 dm high, 

 longer than the leaves ; leaves broadly ovate, cordate or truncate 

 at base, obtuse (the blade 2-11 cm. long) ; umbel proliferous, 

 in a branched panicle ; flower 8-10 ram. broad ; stamens 12 ; 

 ityles longer than the ovary ; achenes with a conspicuous erect 

 beak. (E. rostratus Engelm.) — Borders of ponds and ditches, 111. to Kan., 

 s. Cal., and Fla. Fig. 43. Var. lanceolXtus (Engelm.) 

 Mackenzie & Bush is a low form which has the leaves 

 lanceolate with an acute base. — 111., Mo. 



3. E. radicans (Nutt.) Engelm. Stems or scape prostrate, 



creeping (6-12 dm. long), proliferous, bearing many whorls 



of flowers ; leaves somewhat truncately heart-shaped, obtuse 



(5-20 cm. broad), long-petioled ; flowers 12-20 mm. broad; 



" * stamens about 21 ; styles shorter than the ovary; achenes 



44. E. radicans. with a short incurved beak, the keeled back denticulate. 



a. Er. xl. — About ponds, etc., 111. to N. C. and Fla., w. to Kan. and 



b. Achene x 8. Tex. Fig. 44. 



4S E. corfflfolins. 

 Achene xS. 



4. ALIS.MA L. Water Plantain 



Petals involute in the bud. Ovaries many in a simple circle on a flattened 

 receptacle, forming flattened coriaceous achenes, which are dilated and 2-3- 

 keeled on the back. — Scape with whorled panicled branches. Flowers small, 

 white or t>ale rose-color. (The Greek name ; of uncertain derivation.) 

 ,!> 1. A. Plantagfl-aquAtica L. Perennial by a stout proliferous corm ; leaves 

 long-petioled, ovate or oblong, acute, mostly rounded or heart-shaped at base, 

 3-9-nerved; scapes 1 or 2; jjaraicZe loose, pyramidal, 3-6 dm. long, much overtop- 



