453 
1. ARISZAMA Martius. (INDIAN TURNIP.) 
Low perennial herbs, with a tuberous rootstock or corm sending up 
a simple scape sheathed with the petioles of the veiny leaves, spathe 
convolute below and mostly arched above, monoecious flowers covering 
only the base of the spadix which is elongated and naked above, no 
floral envelopes, sterile flowers above the fertile with subsessile 2 to 
4-celled anthers opening by pores or chinks at apex, fertile flowers 
‘ach a one-celled ovary with depressed stigma, fruit a 1 to few-seeded 
scarlet berry. 
1. A. Dracontium Schott. (DRAGON Roor.) Corms clustered: petiole 3 to6 dm. 
long (much longer than the peduncle); leaf solitary, pedately divided into 7 to 11 
oblong-lanceolate pointed leatlets: spadix often androgynous, tapering to a long 
slender point beyond the oblong and convolute pointed greenish spathe.—Extending 
into Texas from the east. 
LEMNACER, (DUCKWEED FAmMILy.) 
Minute stemless plants, floating free on the water, destitute of dis- 
tinct foliage, being merely a frond producing one or few moncecious 
flowers from the edge or upper surface, with commonly hanging roots 
underneath, ovules rising from the base of the cell, fruit a 1 to 7-celled 
utricle, and the large seed with apex (radicle end) of seed-coat separa- 
ble as a lid. 
1. Spirodela. Frond 7 to 11-nerved, with several rootlets. 
2. Lemna. Frond 1 to 5-nerved, with a single rootlet, 
3. Wolffia. Frond thick, very minute, without rootlets. 
1. SPIRODELA Schileiden, 
Frond 7 to 11-nerved or more, with several rootlets having axial vas- 
cular tissue, anthers 2-celled by vertical partition and longitudinally 
dehiscent, and two ovules; otherwise as Lemna. 
1. S. polyrrhiza (L.) Schleid. Frond round-obovate (4 to 8 mm. long), thick, pur- 
ple and rather convex beneath, dark green above, palinately (mostly 7)-nerved, 
(Lemna polyrrhiza L.)—Very common in ponds and slow streams of central and west 
Texas. 
2. LEMNA L. (DUCKWEED.) 
Fronds 1 to 5-nerved, with single rootlet (destitute of vascular tis- 
sue), flowers (usually 3 together surrounded by a spathe, 2 consisting 
of a stamen and 1 of a pistil) produced from a cleft in the margin of the 
frond, slender filaments, 2-celled didynamous anthers, 1-celled ovary 
with 1 to 7 seeds, and the style and truncate stigma simple. 
* Ovule solitary: frond 1 to 3-nerved. 
+ I’ronds oblong, staiked at base, remaining connected. 
I. L, trisulea L, Fronds thin, oblong to oblong-lanceolate (12 to 18 mm, long), 
attenuate at base into a slender stalk, denticulate at tip, obscurely 3-nerved, often 
without rootlet, usually several series of offshoots remaining connected: spathe sac- 
like: seed ovate, with small round operculum.—Ponds and slow waters about the 
Pecos and San Felipe creek. 
11874—No, 3——8 
