86 



ALISMACEAE. 



1. Echinodorus radicans (Nutt.) Engelm. Creeping Bur-head. 



Sagitlaria radicans Nutt. Trans. Am. Phil. Soc. 



Fchinodorus radicans Engelm. in A. Gray, 



Man. 1-<1. 2, 438- l8 56. 



Leaves coarse, ovate, obtuse, cordate, 2'- 

 8' long, i ft'-lW wide, marked with short 

 pellucid lines, the nerves 5-9, connected by 

 netted cross-veins. Petioles sometimes 20' 

 long; scapes creeping, 2-4 long, slightly 

 scabrous, often rooting at the nodes ; verti- 

 cils distant ; bracts linear-lanceolate, acum- 

 inate, dilated at the base ; pedicels 3-12, un- 

 equal, i'-2>'long, slenderer filiform; sepals 

 persistent, much shorter than the heads; 

 petals larger, obovate, about 3" long ; sta- 

 mens about 20; style shorter than the ovary ; 

 achenes numerous, about 2" long, 6-10- 

 ribbed, with 2-several oval glands on each 

 side and beaks about one fourth their length ; 

 fruiting heads \" in diameter. 



In swamps. Illinois to North Carolina and 

 Florida, west to Missouri and Texas. June-July. 



2. Echinodorus cordifolius (L>) Griseb. Upright Bur-head. (Fig. 191.) 



Alisma cordifolia L,. Sp. PI. 343- I 753- 

 Echinodorus restrains Engalm. in A. Gray, 



Man. Ed. 2, 538. 1856. 

 Echinodorus cordifolius Griseb. Abb. Kon. 



Gesell. Wiss. Gott. 7: 257. 1857. 



Leaves variable in form, often broadly 

 ovate, obtuse, cordate at the base, 6 / -8 / long 

 and wide, but in smaller plants sometimes 

 nearly lanceolate, acute at each end and but 

 i / -2 / long; petioles angular, striate, I'-io' 

 high ; scapes i or more, erect, 5'-\& tall ; 

 flowers 3-6 in the verticils ; pedicels % f - l A f 

 long, erect after flowering ; bracts linear- 

 lanceolate, acuminate, dilated at the base; 

 sepals shorter than the heads; petals 2 // ~3 // 

 long; stamens often 12; styles longer than 

 the ovary ; fruiting heads very bur-like, 2"- 

 3" in diameter; achenes about \ l /i fr long, 

 narrowly obovate or falcate, 6-8-ribbed; beak 

 apical, oblique, about one-half the length of 

 the achene. 



In swamps and ditches, Illinois to Florida, 

 west to Missouri and Texas. Also in tropical 

 America. June-July. 



3. LOPHOTOCARPUS T. Durand, Ind. Gen. Phan. 627. 1888. 

 [LOPHIOCARPUS Miquel, PI. Arch. Ind. i: Part 2, 50. 1870. Not Turcz. 1843.] 



Perennial, bog or aquatic herbs with basal long-petioled sagittate or cordate leaves, 

 simple erect scapes bearing flowers in several verticils of 2-3 at the summit, the lower per- 

 fect, the upper staminate. Sepals 3, distinct, persistent, erect after flowering and enclosing 

 or enwrapping the fruit. Petals white, deciduous. Receptacle strongly convex. Stamens 

 9-15, hypogynous, inserted at the base of the receptacle. Filaments flattened. Pistils 

 numerous ; ovule solitary, erect, anatropous ; style elongated, oblique, persistent. Aoheues 

 winged or crested. Embryo horseshoe-shaped. [Greek, signifying crested fruit] 



About 3 speciex. tlu- following of eastern North America, the others of tropical America. 



