MANUAL OF THE GRASSES OF THE UNITED STATES 



737 



branaceous. Mostly tall perennials 

 with broad flat blades, contracted 

 into a petiole, and open or contracted 

 panicles of glabrous spikelets. Type 

 species, Olyra latifolia. Name from 

 ohira, an old Greek name for a kind 

 of grain. 



1. Olyra latifolia L. (Fig. 1124.) 

 Glabrous perennial, bamboolike in 

 aspect, commonly 3 m. tall, with flat, 

 firm, asymmetrically lanceolate-ob- 

 long, abruptly acuminate blades 

 commonly 20 cm. long and 5 cm. 

 wide, and ovoid panicles 10 to 15 cm. 

 long, the branches stiffly ascending or 

 spreading, each bearing a single large 

 long-acuminate pistillate spikelet at 

 the thickened summit and several 

 small slender-pediceled staminate 

 spikelets along the branches. % — 

 Said to occur in the region of Tampa 

 Bay, Fla., but the record is doubtful; 

 tropical America; Africa. 



Figure 1123. 



-Amphicarpum muhlenbergianum, X 1. 

 (Chapman, Fla.) 



TRIBE 13. ANDROPOGONEAE 



148. IMPERATA Cyrillo 



Spikelets all alike, awnless, in pairs, unequally pedicellate on a slender con- 

 tinuous rachis, surrounded by long silky hairs; glumes about equal, mem- 

 branaceous; sterile lemma, fertile lemma, and palea thin and hyaline. Peren- 

 nial, slender, erect grasses, from hard scaly rhizomes, with terminal narrow 

 silky panicles. Type species, Imperata cylindrica. Named for Ferrante Im- 

 perato. 



Spikelets 4 mm. long, the hairs at base twice as long; panicle oblong, rather lax. 



1. I. BRASILIENSIS. 



Spikelets 3 mm. long, the hairs three times as long; panicle elongate.. 2. I. brevifolia. 



1. Imperata brasiliensis Trin. (Fig. 

 1125.) Culms 50 to 100 cm. tall, from 

 scaly rhizomes; leaves crowded be- 

 low, 3 to 8 mm. wide, the lower blades 

 elongate, those of the culm short, the 

 uppermost much reduced; panicle 

 dense, pale or silvery, mostly 10 to 

 12 cm. long; spikelets 4 mm. long. 

 % — Pinelands, prairies, and Ever- 

 glades, southern Florida and Ala- 

 bama; tropical America at low alti- 

 tudes. 



2. Imperata brevifolia Vasey. Sat- 

 intail. (Fig. 1126.) Resembling I. 

 brasiliensis; culms 1 to 1.5 m. tall; 

 leaves less crowded at base, all but 

 the uppermost elongate; panicle 15 to 



30 cm. long; spikelets 3 mm. long, the 

 hairs three times as long. % (I. 

 hookeri Rupr. ex Hack.) — Desert re- 

 gions, western Texas to southern 

 California, Utah, and Nevada; Mex- 

 ico. 



Imperata cylindrica (L.) Beauv. 

 Cogon grass. Spikelets 4 to 5 mm. 

 long, the hairs as long as in /. brevi- 

 folia. 91 — Ballast, Portland, 

 Oreg. ; recently introduced in Florida 

 and spreading in the west central part 

 of the State. It is fairly good forage, 

 but because of the strong creeping 

 rhizomes it spreads into cultivated 

 ground and is difficult to eradicate. 



