22 | ALISMACEAE 
1. E. radicans (Nutt.) Engelm. Stem creeping near the base: leaf-blades 
ovate or elliptie, 5-20 em . long: scape often creeping, the flower-whorls remote: 
petals a : 
-hea 8 
thiek: achene long, short-beaked.— 
Pond- cU d | difehes, various provinces, 
Fla. to Tex., Calif, Kans, and D. C. 
(Mem.) 
2. E. cordifolius (L.) Griseb. Stem ereet 
or ascendi ing: leaf-blades o to 
broadly ovate, 4-20 em. long: scape 1-5 dm 
tall, the ae bed e. remote than in 
E. radicans: petal E ng: pod 
head 4-6 mm. Feu ae 2.5—9 
SE long-beaked. [£. Nerone Engelm. ae 
Swamps, ditches, and ponds, various pro- 
un Fla. to Tex. ., Kans., and Ill.—(W. I., Mex., 
4, LOPHOTOCARPUS T. Durand. Leaves often with basal lobes, but 
variable. Flowers monoecious, the upper ones staminate. Stamens 9-195. 
Achenes in a head embraced by the calyx.— 
About 7 species, besides the following and 
several that range westward to California, 
others occur in tropical America.—Sum.— 
fall 
1. L. calycinus (Engelm.) J. G. 
br; : achene ov 
n mg beaked.—Wet grounds, ep 
and ponds, various provinees, Ala. le 
S. Dak., and Del 
SAGITTARIA L. Leaves often with basal lobes, sometimes lobeless, 
or mere phyllodia. Flowers monoecious or dioecious, the upper ones ane! 
staminate. Corolla white. Stamens mainly numerous. Achenes numerous 
ely few, in dense heads.—Comprises about 40 species of wide e Di 
distribution. Several species produce edible starchy tubers which were ex- 
tensively used by the aborigines.—Mainly sum.—fall, or all year S.—ARROW- 
EADS. SWAMP-POTATOES 
Fruit- Aere e reflexed or re SUBULATAE. 
Fruit-bearing pedicels ascending. 
Leaf-blades without basal lobes. II. ANGUSTIFOLIAE. 
Leaf-blades with basal lobes. III. LATIFOLIAE. 
Sepals of the pistillate flowers accrescent and ultimately 
appressed to the fruit-heads. IV. MONTEVIDENSES. 
SUBULATAE 
Filaments glabrous. 
Tutores e Py ie except in robu 
DE e x 1. S. subulata. 
Aquatie plants with elongate leaves: ‘achene 
short-beaked. 
