26 POACEAE. 



13. ECHINOCHLOA Beauv. Agrost. 53. pi. 11, f. 2. 1812. 



Usually tall grasses, commonly annuals, with broad leaves and a terminal 

 inflorescence consisting of one-sided racemes racemosely or paniculately ar- 

 ranged. Spikelets 1-flowered, singly disposed, or in smaller racemes or clusters 

 on the ultimate divisions of the inflorescence. Scales 4, the outer 3 mem- 

 branous, hispid on the nerves, the third and usually also the second scale awned, 

 or sometimes merely awn-pointed, the awn often very long; fourth scale in- 

 durated, shining, frequently pointed, enclosing a palet of similar texture and a 

 perfect flower. Stamens 3. Styles distinct. Stigmas plumose. Grain free. 

 [Greek, in reference to the stout hispid hairs of the spikelets.] Species about 

 12, mostly in warm and tropical countries. Type species: Panicum Crus-galli L. 



Outer scales of the spikelet not awned: spikelets 2.5-3 mm. long. 1. E. colonum. 

 ^uter scales of the spikelet, at least one of them, awned ; spikelets 



2.5-4 mm. long, exclusive of the awns. 2. E. Crus-galli. 



1. Ecninochloa colonum (L.) Link, Hort. Berol. 2: 209. 1833. 



Pamcum colonum L. Syst. Nat. ed. 10, 870. 1759. 



'Culms tufted, smooth and glabrous, 1.5-7.5 dm. tall, often decumbent and 



rooting at the lower nodes. Sheaths compressed, usually crowded; leaves flat, 



2.5-17 cm. long, 2-8 mm. wide; inflorescence composed of 3-18, 1-sided, more 



or less spreading dense racemes 6-50 mm. long, disposed along a 3-angled 



rachis and generally somewhat exceeding the length of the internodes ; spikelets 



single, in pairs, or in 3 's in 2 rows on one side of the hispidulous, triangular 



rachis, obovate, pointed, the first scale about one-half as long as the spikelet, 



3-nerved, the second and third scales a little more than 2 mm. long, awnless, 



5-nerved, hispid on the nerves, the fourth scale cuspidate. 



Waste places, Turks Islands : Virginia to Florida and Texas ; tropical regions. 

 Jungle Rice. 



2. Echinochloa Crus-galli (L.) Beauv. Agrost. 53, 161. 1812. 



Panicum Crus-galli L. Sp. PI. 56. 1753. 



Culms 6-12 dm. tall, often branching at base. Sheaths smooth and 



glabrous; leaves 1.5-6 dm. long, 6-25 mm. wide, glabrous, smooth or scabrous; 



panicle composed of 5-15 sessile, erect or ascending branches, or the lower 



branches spreading or refiexed; spikelets ovate, green or purple, densely 



crowded in 2-4 rows on one side of the rachis; second and third scales about 3 



mm. long, scabrous or hispid, the third scale more or less awned, empty, the 



fourth ovate, abruptly pointed. Widely distributed as a weed in all cultivated 



regions. Naturalized from Europe. 



Waste places, Turks Islands : widely distributed in temperate and subtropical 

 regions. Native of the Old World. Baknyard-grass. 



14. OPLISMENTJS Beauv. Fl. Owar. 2: 14, pi. 68. 1807. 



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, awn- 

 less, ehartaceous, finally indurated, enclosing a shorter palet of similar texture 

 and a perfect flower. Stamens 3. Styles distinct to the base. Stigmas plu- 



