86 ALISMACEAE. 
1. Echinodorus radicans (Nutt.) Engelm. Creeping Bur-head. (Fig. 190.) 
Sagitlaria radicans Nutt. Trans. Am. Phil. Soc. 
CII.) 5: 159. 1833-37. ; 
Echinodorus radicans Engelm. in A, Gray, 
Man. Ed. 2, 438. 1856. 
Leaves coarse, ovate, obtuse, cordate, 2/- 
8’ long, 114/-74’ 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, 1’-2!4’ long, slender or 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 4’’ in diameter. 
In swamps, Illinois to North Carolina and 
Florida, west to Missouri and Texas. June-July. 
2. Echinodorus cordifdlius (L.) Griseb. Upright Bur-head. (Fig. 191.) 
Alisma cordifolia I,. Sp. Pl. 343. 1753. 
Echinodorus rostratus Engelm. in A. Gray, | 
Man. Ed. 2, 538. 1856. 
Echinodorus cordifolius Griseb. Abh. 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 
1/-2’ long; petioles angular, striate, I/—10” 
high ; scapes 1 or more, erect, 5/—16/ tall; 
flowers 3-6 in the verticils; pedicels 4/—1%4’ 
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 114’ long, 
narrowly obovate or falcate, 6-S-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. 
[LopHrocarpus Miquel, Fl. Arch. Ind. 1: Part 2, 50. 1870. Not Turez. 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. Achenes 
winged or crested. Embryo horseshoe-shaped. ([Greek, signifying crested fruit.] 
About 3 species, the following of eastern North America, the others of tropical America. 
