248 LEMNACEAE 
A yara of e Be em TARO) —is ae = s 
edible in rida eaped to marshes and roadsides 
places. E^ is ees aed leaf. blades 
Faminy 2. LEMNACEAE — Duckweep FAMILY 
Floating iid E chiefly of very small, often minute, fleshy 
Ages. sometimes with 1 or several roots. Propagative pouches 1 or 
2 in each bs y. Fie ce monoecious, one or two staminate and one 
pistillate in in ti en Staminate flowers consist of 1 stamen. 
Pistillate enm consist of 1 el. Fruit a utricle—Four genera and 
2 species, widely distributed E the smallest of the flowering 
plants. 
Plant-body not disk-like, rootless : propagative pouch solitary. Tribe I. WOLFFIEAE. 
Plant-body disk-like, with a single root or a cluster of roots 
propagative pouches 2. ribe II. LEMNEAE. 
I. WOLFFIEAE d 
Plant-body very thick or globos 1. BRUNERIA. 
Plant-body thin, tongue-like or A EE N 2. WOLFFIELLA. 
II. LEMNEAE 
Plant-body inconspicuously nerved: root scree without fibro- 
vascular bundle, 3. LEMNA. 
Plant-body con spicuously nerved: roots 2-several, each with a 
fibrovascular bundle. 4, SPIRODELA. 
1. BRUNERIA Franch. Plant- peg wo» denim or oa Pro: 
pagative pouch funnelform. Spadix 1 pistillate flow 
bursting through the upper surface M "n 202 rs asd 
Several species, most abundant in tropical and subtropical regions.—Mup- 
Plant-body smooth, somewhat flattened above, gibbous beneath, 
brown-punctate. 1. B. punctata. 
du oed ellipsoid or globose, with 2-3 papules on dorsal sur- 
e, not pune 2. B. columbiana. 
1. B. punctata (Griseb.) Nieuw. Plant- 
hody boat- ai indi to ovoid-ellipsoid, o 9 
0.58—0.82 flat or nearly so 
duni gr aay ising a t the apex: tis- o 
u 
o 
on the 
Coastal Plain and occasionally other 
provinees, Fla. io Tex. and Ont 
B. columbiana (Kar st.) Nieuw. 
Plant we globose to ellipsoid, 0.48-1 
m. long, the upper surface convex, with 
ipe 
Stomata: tissue of uniform uo cells. [W. columbiana Karst.]—Floating be- 
neath the surface of stagnant water, various provinces, Fla. to La., Minn., Ont., 
and Mass 
