MANUAL OF THE GRASSES OF THE UNITED STATES 



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articulating above the glumes and 

 between the florets; glumes about 

 equal, nearly equaling the lower lem- 

 ma, with several parallel nerves ; lem- 

 mas 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 spe- 

 cies, Cottea pappophoroides. Named 

 for Heinrich Cotta. 



1. Cottea pappophoroides Kunth. 

 (Fig. 301.) Softly pubescent through- 



out; 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 conspicuous, at least the middle 

 awn spreading. % — 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. 



39. PAPPOPHORUM Schreb. Pappusgrass 



Spikelets 4- to 6-flowered, the lower 1 to 3 fertile, the upper reduced, the 

 rachilla disarticulating above the glumes, but not or only tardily between the 

 florets, the internodes very short; glumes nearly equal, keeled, thin-mem- 

 branaceous, as long as the body of the florets, 1-nerved, acute ; lemmas rounded 

 on the back, firm, obscurely many-nerved, dissected above into numerous 

 spreading, unequal awns, the florets falling together, the awns of all forming 

 a pappuslike 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 species, Pappophorum alopecuroideum 

 Vahl. Name from Greek pappos, pappus, and phoros, bearing, alluding to the 

 pappuslike crown of the lemma. Our species are of minor economic importance. 



Panicle spikelike, tawny or whitish 1. P. mucronulatum. 



Panicle narrow but rather loose, pinkish 2. P. bicolor. 



1. Pappophorum mucronulatum 



Nees. (Fig. 302.) Culms erect, 60 to 

 100 cm. tall; blades flat to subinvo- 

 lute, 2 to 5 mm. wide; panicle spike- 

 like, tawny or whitish, tapering at 

 summit, 10 to 20 cm. long; spikelets 

 short-pediceled with 1 or 2 fertile flo- 

 rets and 2 or 3 sterile reduced ones, the 

 rachilla disarticulating below the fer- 

 tile floret and tardily above it ; glumes 

 1-nerved; fertile lemma subindurate, 

 the nerves obscure, villous toward 

 base, dissected into numerous unequal 

 awns 2 to 5 mm. long, the body about 

 3 mm. long. % (P. apertum Mun- 

 ro.) — Low places on plains and in 

 valleys, Texas, Arizona, and northern 

 Mexico; South America; wool waste, 

 Maine. 



2. Pappophorum bicolor Fourn. 

 (Fig. 303.) Culms erect, 30 to 80 cm. 



tall; blades flat to subinvolute, 1 to 5 

 mm. wide; panicle mostly 10 to 15 

 cm. long, usually pink-tinged, rather 

 loose, the branches 1 to 4 cm. long; 

 spikelets on pedicels 1 to 5 mm. long, 

 with 2 or 3 fertile florets and 1 or 2 

 sterile reduced ones, all about the 

 same height in the spikelet, the ra- 

 chilla not separating between the flo- 

 rets ; glumes 1-nerved ; lemmas some- 

 what indurate, obscurely nerved, 

 pilose on the callus and on the lower 

 half to two-thirds of the midnerve and 

 margins, dissected into about 12 

 somewhat unequal scabrous awns 2 to 

 4 mm. long, the body about 3 mm. 

 long, the awns about as long. 2[ 

 — Open valley land, Texas, Arizona 

 (La Noria, near Monument 111), and 

 Mexico. 



