84 A I > I S M A ( ' !: A K ( WATER PLANT A I N FA M I L \ ' ) 



** Species of the interior; leaf-blades relatively large, sagittate witli Imml 



triangular auricles. 



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

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

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

 curving or procumbent, 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 Dak. and southw. 



Var. maximus (Engelm.) Robinson. 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. (Moseley) and southw. 



3. ECHIN6DORUS Richard. 



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

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

 flowers on rather short pedicels, in whorls of 3-6 or more. 

 Fl. summer and autumn. (Name from tx^udv, prickly, 

 or from ^x*" 05 ? an d Sop6s, 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. ) 



1. E. tenSllus (Martius) Buchenau. Hrapcs 1.5-1(1 i-m. 

 high ; shoots often creeping and proliferous ; submersed 

 leaves lance-linear phyllodia, emersed leaves petiolate with 

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



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

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

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

 (Alisma Martius ; 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 



in a branched panicle ; flower 8-10 mm. broad; stamens 12; Achem "xV." 

 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. LANCEOL\TUS (Knirelm.) 



Mackenzie & Bush is a low form which has the leaves 



lanceolate with an acute base. 111., Mo. 

 "^a :*. E. radicans (Nutt.) Engelm. Stems or scape prostrate, 



W 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; 

 " f ' stamens about 21 ; styles shorter than the ovary; acln-mx 



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

 <t. Fr. x 1. About ponds, etc., 111. to N. C. and Fla., w. to Kan. and 



/>. Achene x 3. Tex. FlG. 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 ({reek name ; of uncertain derivation.) 



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

 loim-pctioled, ovate or oblong, acute, mostly rounded or heart-shaped at base, 

 :: '.'-nerved; scapes 1 or 2; panicle loose, pyramidal, 3-6 dm. long, murfi nn-rfop- 



