84 ALISMACEAE (WATER PLANTAIN FAMILY) 



» * SpBties of the interior ; leaf-hlades relatively large, sagittate with broad 

 triangular auricles. 



2 L. calycinus (Engelm.) J. G. Sm. Taller (L5-4 dm. high) ; leaf-blades 

 (t«eply sagittate, thin, 10-15-nerved, 4-8 cm. broad, the auricles triangular, 

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

 curving or procumbent, l-4"dm. long, usually bearing 3-4 whorls of flowers ; 

 head of carpels about 1 cm. in diameter. ySagittaria Engelm.) — Muddy banks, 

 Mich, to Dak. and southw. 



Var. maximus (Engelm.) Robinson. Leaf-blades very large {^6 dm. wide), 

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

 Inflorescence stout, sometimes branched. {Sagittaria caiycina, var. Engelm. > 

 — O. {Moseley) and southw. 



3. ECHIN6dORUS Richard. 



Petals imbricated in the bud. Stamens 8-21 or more. — Mostly annuals, with 

 the habit of S(i(iiitnria, the naked stems sparingly branched or simple, and the 

 tlowers on rather short pedicels, in whorls of 8-6 or more. 

 Fl. summer and autumn. (Name from extvdodrjs, prickly, 

 or from ix'ivos, and 8op6s, a leathern bottle, applied to the 

 ovary, which is in most species armed with the persistent 

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



1. E. tenellus (Martins) Buchenau. Scapes l.o-lO cm. 



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-fiowered ; pedicels reflexed in fruit ; flower mm. 



42. E. tenellus. broad ; stamens 9 ; styles much shorter than the ovary ; 



"' ^^' ^l\ q *^ acnenes beakless, 8-ribbed, reddish brown, without glands. 



c. Achene 6. (^AUsma Alartius ; Helianthium Britton ; E. parvulus 



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, 43 e. cordSfolius. 

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

 styles 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. lanceolatus (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 trimcately heart-shaped, obtuse 



(5-20 cm. broad), long-petioled ; flowers 12-21) mm. broad; 



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



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



a. Fr. X 1. — About ponds, etc., 111. to N. C. and Fla., w. to Kan. and 



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



4. ALISMA 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 pale rose-color. (The Greek name ; of uncertain derivation.) 



1. A. Plantago-aquatica L. Perennial by a stout proliferous corm ; leaves 

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

 3-9-nerved ; scapes 1 or 2; pa wicZe loose, pyramidal, 3-6 dm. long, 7nuch overtop- 



