ALISMACEAE 21 
Carpels borne in one series: achenes verticillate. I. ALISMEAE. 
Carpels borne in several spiral series: achenes capitate. II. SAGITTARIEAE. 
. I. ALISMEAE 
Flowering stem much branched, the pedicels very slender and 
wiry. 
1. ALISMA. 
II. SAGITTARIEAE 
Flowers all perfe 
Style not Bd. fruit-head not echinate: achene turgid, 
beakless or only obscurely beaked. 2. HELANTHIUM. 
Style apical: fruit-head echinate: achene flat, promi- 
nently beake 3. ECHINODORUS. 
Flowers polygamous or dioecious, or monoecious—the lower 
flow of the inflorescence perfect or pistillate, the 
uot Ges staminat 
Lower flowers of the d evextonke perfect. 4. LOPHOTOCARPUS. 
Lower flowers of the inflorescence pistillate. . .9. SAGITTARIA 
1. ALISMA L. Leaves without basal lobes. Flowers perfect, in com- 
pound panicles. Stamens mostly 6. Achenes in 1 whorl.—About 10 species, 
mostly in temperate and tropical regions. 
Wes 7) 
"fh 
T 
A 
TO 
A. subcordatum Raf. Leaves erect; 
NA entire, 3-15 em. long, long- petioled: 
seape 1—10 dm . tall, the Him or pedi- 
a : 
T 
ibe 
ae 
IM 
cels, whorled in 3's to 1 se ls obtuse 
mm. long: pera ee depressed, 
3 . wi achene 1.5— 
Plantago (Chapm. ]— 
[4. )]—((OWaT 
PLANTAIN.)—Swamps, ditches, and shallow 
water, various provinces, Fla. to Tex., Minn., 
and Ma ass.—Spr.—fall. 
2. HELANTHIUM Engelm. Leaves without basal lobes, the blades nar- 
row. Flowers perfect, borne in racemes. Stamens 6 or 9. Achenes borne 
in an inconspicuous naked head.—Two | 
species, one in Cuba and the following. 
H. par arvulum (Engelm.) Britton. Ps 
long 3—1 all with a ienminal 
whorl of 2-8 rp petals 1 .0—2 mm. 
fruit-head 3—4 thiek: achene barely 1 
mm. long. [Echino odorus parvulus Engelm.] 
—Muddy place : or shallow water, various 
provinces, Fla. to Tex T and Mass.— ~ 
(W. I., Me B -fal 
3. ECHINODORUS L. C. Rich. Leaves with rounded basal lobes. Flow- 
Ach 
ers perfect, in racemes or panicles. Stamens 12-30. enes borne in 
bristly naked head.—About 15 species, all n the following mostly Mee 
Ameriean.—Spr.-sum.—BUR-HEADS. MUD-BABIES. CREEPING WATER-PLANTAINS. 
Flowers, and fruit-heads, borne on pliable curved pedicels: style shorter than the 
ovary: achene-beak about l4 as long as the body. 1. E. radicans. 
Flowers, and E eei uri on Stift spreading pedicels: UA 
ry: 
bo 
2. E. cordifolius. 
