ALISMACEAE 
Leaves with small floating blades: inflores- 
cence simple: crests of 2s achene with 
mere shallow undulatio 
Leaves elongate ligulate phyllodia : inflores- 
e sometimes branched: crests of the 
hene with deep undulations 
Inflorescence branched : phyllodia slenderly attenuate. 
Filaments pubes 
II. ANGUSTIFOLIAE 
MSIE 2 m. dress c 2. long as those of the 
nate on riy 
ruin dilated, “relatively Shor 
Lea ee terete 3-sided, often imperfectly 
eve 
Anther jouer than n filament: achene with 
several facial wing 
Anther shorter M. “hé filament: achene with 
Achene oval o broadly elliptic. 
Achene cune 
Beak pru horizontal at the top of the 
achen e-body 
Beak e Borde much below the top of 
ache 
y. 
YüUOR Seed OG simple: lower bracts ovate, 
united to the moe achene with 
lateral ribs or win 
Inflorescence widely Dum nehed: lower 
bracts lanceolate, aite at the base: 
achene without lateral ribs or wings. 
Filament not dilated, sle nder 
Bracts and sepals granular- -papillose. 
Bracts and sepals ri 
Achene more or jo faleate, eee beaked, 
the dorsal wing thick nd e 
aaan not falcate, abruptly bon cd: the dorsal 
wing usually thin and crested. 
din of the pistillate flowers vy short or nearly 
ranting. 
Fruit. head not echinate: achene broadly winged and 
shor MR ME anther broadly elliptie, about as long 
as the filamen 
Fruit-head echin ate: achene narrowly winged and 
ee anther suborbicular, shorter than the 
me 
III. LATIFOLIAE 
Achene minutely or inconspicuously beaked. 
Achene prominently long-beake S 
Beak s r nearly 
Ue m D edlceis. bracts, and sepals 
t 
Achene less than 4 mm. long; beak horizontal 
or declined, narrow, much smaller than the 
body from Which it is differentiated : bracts 
los 
tomentu 
Achene éd 4 long; beak horizontal- 
ascending, broad, larger than the body. with 
Brem it is ntinuous: bracts granular- 
escent. 
— rachis, pedicels, bracts, and sepals 
1 
Beak ere 
Filament pubescent. 
Pistillate ae very short: sepals and bracts 
glabrou 
Pistillate “pedicel elongate: sepals and bracts 
pu 
Filament IDS 
Bas lobes p the leaf-blade acute or acumi- 
Basal E of the leaf-blade rounded. 
V. MONTEVIDENSES 
I 
Robust plant: leaf-blades 1-5 dm. long and wide: scape 
up to 1 m. tall. 
nAaR 
n n 
wR 
. stagnorum. 
lorata. 
filiformis. 
. platyphylla. 
. teres. 
isoetiformis. 
. cycloptera. 
. Mohr. 
. graminea. 
. Chapmanii. 
. falcata. 
lancifo lia. 
. angustifolia. 
. macrocarpa. 
. rigida. 
. graminea. 
pubescens. 
. ornithorhyncha. 
. latifolia. 
rigida. 
. viscosa. 
. S. longirostra. 
. Ñ. 
australis 
montevidensis. 
