MANUAL OF THE GEASSES OF THE UNITED STATES 



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36. COTTEA Kunth 



Spikelets several-flowered, the uppermost reduced, the rachilla 

 disarticulating above the glumes and between the florets; glumes 

 about equal, nearly equaling the lower lemma, with several parallel 

 nerves; lemmas rounded on the back, villous below, prominently 9- 

 to 11-nerved, some of the nerves extending into awns of irregular 

 size and some into awned teeth; palea a little longer than the body 

 of the lemma, the keels near the margin. An 

 erect tufted branching perennial with flat blades 

 and oblong loose panicle. Type species, Cottea 

 pappophoroides. Named for Heinrich Cotta. 



1. Cottea pappophoroides Kunth. (Fig. 435.) 

 Softly pubescent throughout; culms 30 to 50 cm 

 tall; blades 3 to 7 mm wide; panicle 8 to 15 cm 

 long, the branches loosely ascending; spikelets 

 4- to 7-flowered, 5 to 7 mm long, about 5 mm 

 wide, green or purplish; glumes 4 to 5 mm long; 

 lemmas 3 to 4 mm long, the basal hairs con- 

 spicuous, at least the middle awn spreading. 

 Qi — Plains and dry hills, western Texas to 

 southern Arizona, south to central Mexico; 

 Ecuador to Argentina. Cleistogamous spikelets, 

 usually reduced to a single floret, are found in 

 the lower sheaths, and often large, very turgid 

 ones at the very base. Not abundant enough 

 to have economic importance. 



37. PAPPOPHORUM Schreb. Pappusgrass 



Spikelets 2- to 5-flowered, the upper reduced, 

 the rachilla disarticulating above the glumes but 

 not or only tardily between the florets, the inter- 

 nodes very short; glumes nearly equal, keeled, 

 thin-membranaceous, as long as the body of the 

 florets or longer, 1- to several-nerved, acute; lem- 

 mas rounded on the back, firm, obscurely many- 

 nerved, dissected above into numerous spreading 

 awns, the florets falling together, the awns of all 

 forming a pappus-like crown ; palea as long as the 

 body of the lemma, the nerves near the margin. 

 Erect tufted perennials, with narrow or spikelike 

 whitish to tawny or purplish panicles. Type spe- 

 cies, Pappophorum alopecuroideum Vahl. Name from Greek pappos, 

 pappus, and phoros, bearing, alluding to the pappus-like crown of the 

 lemma. Our species are of minor economic importance, though the 

 first two may constitute a fair proportion of the forage on sterile hills. 



Awns plumose; panicle plumbeous, usually less than 5 cm long. 1. P. wrightii. 

 Awns scabrous; panicle tawny to pink, usually more than 5 cm long. 



Panicle spikelike, tawny or whitish 2. P. mtjcronulattjm. 



Panicle narrow but rather loose, pinkish 3. P. bicolor. 



Figuhe 434—Blcpharidachne 

 hiaclovii. Plant, X 1; fertile 

 floret, X 5. (Type.) 



55974°— 35 15 



