126 LIST OF SEEDS, BULBS, TUBERS, ETC. 
a short neck 6—9” in diameeter. N. Juteum, 
variety pumilum (Man.). Maine to Pennsylvania and 
Minnesota and northward. 
N. sagillifolium, Pursh:—Rootstock stout, leaves 
narrowly oblong to oblong-lanceolate, with a short 
sinus, G—15 long; flowers small (1 broad). 
Southern Indiana and Illinois (Schneck), and south- 
ward. 
LEMNACEE (Duckweed Family). 
Lemna, L.—Duckweed, Duckmeat :—Ovule solitary, 
orthotropous or nearly so; frond one to three nerved, 
thin. 
L. trisulea, L.:—lVronds oblong to oblong-lanceolate 
(6—g long), attenuate at base into a slen- 
der stalk denticulate at the tip, very obscurely three- 
nerved, often without rootlets, usually several series of 
offshoots remaining connected; spathe sac-like; seeds 
ovate, amphitropous, with small round operculum. 
Ponds and springy places, Nova Scotia to New Jersey, 
west to the Pacific. 
L. Valdiviana, Philippi—Fronds_ elliptic-oblong, 
small (about 1 long), rather thick, utricle long 
ovate, pointed by the long style; seed orthotropous, ob- 
long, with a prominent acute operculum. L. Torreyi 
(Austin). Pools, New Jersey and southward, west- 
ward across the continent. : 
L. perpusilla, Vorr.:—Fronds obovate or roundish 
obovate, oblique (1—1$" long), obscurely  three- 
nerved; utricle ovate; style rather long; seed 
orthotropous, ovate or oval, obtuse, with scarcely 
apiculate operculum. New York and New Jersey, west 
to Michigan and Wisconsin. Variety Trinervis (Aus- 
tin) has larger, distinctly three-nerved fronds, and an 
unequally cordate seed. 
