84 POACEAE 
1-2 dm. long, usually 1.5 cm. wide or less: spikelets ovate-lanceolate, acute, 3-3.5 mm. 
long, the silvery white hairs very long and copious, extending much beyond the apex of 
the spikelet. 
On dry hillsides, Texas to Colorado. Also in Mexico. Summer. 
29. ECHINOCHLOA Beauv. 
Often tall grasses, with flat leaf-blades, the inflorescence composed of several to many 
unilateral more or less spreading spike-like racemes. Spikelets 1-2-flowered, lanceolate to 
ovate or orbicular-ovate, crowded in small clusters or racemes in 2 rows on one side of the 
flat rachis. Scales 4, the 3 outer membranous, spiny-hirsute or hispid externally, the first 
much shorter than the spikelet, often awn-pointed, the second and third awn-pointed or 
awned (rarely awnless), the latter bearing the longer awn and rarely enclosing a palet and 
sometimes also a staminate flower ; fourth scale chartaceous, glabrous and shining, at length 
indurated, acute or acuminate, enclosing a shorter palet of similar texture and a perfect 
flower. Stamens 3. Styles distinct. Stigmas plumose. 
Leaf-sheaths glabrous. 
Awn of the third scale not exceeding 4 times the length of the spikelet, some- 
times very short or almost wanting. 
Spikelets 2.5-3 mm. long: lower racemes rarely exceeding the rachis-inter- 
nodes. 1. E. colona. 
Spikelets 4 mm. long; the lower racemes much exceeding the rachis-inter- `’ 
nodes. 2. E. Crus-galli. 
Awn of the third scale 8-15 times the length of the spikelet. 3. E. longearistata. 
Leaf-sheaths, at least the lower ones, densely papillose-hispid. 4. E. Walteri. 
1. Echinochloa colóna (L.) Link. Stems tufted, 1-8 dm. tall, often decumbent 
and rooting at the lower nodes : leaf-sheaths glabrous, compressed ; blades flat, 2-17 cm. 
long, 2-8 mm. wide: inflorescence composed of 3-18 one-sided more or less spreading ra- 
cemes, 6-30 mm. long: spikelets single, in pairs, or in 3's in 2 rows, obovate, pointed, his- 
pid on the nerves, 2.5-3 mm. in length, the fourth scale cuspidate. [Panicum colonum L.] 
In fields and along roadsides, Virginia to Florida, Texas and Mexico. Common in all tropical 
countries. Spring to fall. JUNGLE RICE. 
2. Echinochioa Crüs-gálli (L.) Beauv. Stems 6-12 dm. tall: leaf-sheaths glabrous ; 
blades 1.5-6 dm. long, 6-25 mm. wide, glabrous, smooth or rough: panicle of 5-15 erect 
or ascending branches, or the lower ones spreading or reflexed and sometimes 6-8 cm. long: 
spikelets ovate, densely crowded in 2-4 rows on one side of the rachis, about 4 mm. long, 
exclusive of the awn, hispidulous, hispid on the nerves, the second and third scales more 
or less awned, the fourth abruptly pointed. [Panicum Crus-galli L.] 
In cultivated and waste places throughout North America, excepting the extreme north, and 
widely distributed as a weed in all eultivated areas. Introduced from Europe. Summer and fall. 
BARNYARD GRASS. 
3. Echinochloa longearistàta Nash. Stems 1-2 m. tall, stout: leaf-sheaths gla- 
brous ; blades flat, rough on the upper surface, smooth beneath, 6-12 dm. long, 2-4 cm. 
wide or more : panicle 4-6 dm. long, its branches ascending: spikelets ovate, 3.5—4 mm. 
long, acuminate, hispidulous, the nerves strongly hispid, the awn of the third scale usually 
8-15 times as long as the spikelet. 
In wet ground, South Carolina to Louisiana. Summer. 
4. Echinochloa Wálteri (Pursh) Nash. Stems 9-18 dm. tall, stout : leaf-sheaths, at 
least the lower ones, papillose-hispid ; blades 3 dm. long or more, 1-2.5 cm. wide, very 
rough above : panicle of 10—40 ascending or spreading branches : spikelets ovate-lanceolate, 
densely crowded in 2-4 rows on one side of the rachis, 3-4 mm. long, exclusive of the awns, 
hispidulous, hispid on the nerves, the second and third scales very long-awned, the fourth 
scale ovate-lanceolate, acuminate. 
In marshes and ditches, usually near salt-water, New York to Florida. Summer and fall. 
30. OPLÍSMENUS Beauv. 
Perennial grasses, often decumbent and branched at the base, with broad flat leaf- 
blades and inflorescence composed of spikes, bearing on the lower side scattered clusters of 
a few spikelets. Spikelets 1-flowered. Scales 4, the 3 outer membranous, the first and 
second empty, awned, the first equalling or somewhat shorter than the spikelet, the third 
scale usually awned, empty, or enclosing a small palet, the fourth one shorter than the 
others, obtuse, awnless, chartaceous, finally indurate, enclosing a shorter palet of similar 
texture and a perfect flower. Stamens 3. Styles distinct to the base. Stigmas plumose. 
Oplismenus setàrius ( Lam.) R. & S. Stems prostrate, rooting at the nodes: leaf- 
blades ovate to ovate-lanceolate, acuminate, 1.5-6 em. long: panicle 2-8 em. long, its short 
