GENERA OF GRASSES OF THE UNITED STATES. 
83 
An erect tufted branching perennial, with oblong open panicles. 
Species one; western Texas to southern Arizona and southward to 
Argentina. 
Type species : Cottea pappophoroides Kunth. 
Cottea Kunth, Rev. Gram. 1: 84. 1829. A single species mentioned, from 
Peru. 
This genus is allied to Pappophorum and very closely related to 
Antnoschmidtia of Africa. It differs from the first in the several- 
flowered spikelets that separate between the florets and in the awns 
interspersed with awned teeth. Anthoschmidtia differs in having 
glumes longer than the florets and in having lemmas with five awns 
alternating with four lobes. 
Cottea pappophoroides Kunth (fig. 40) is not abundant enough to 
have agricultural importance in the United States. Cleistogenes are 
produced in the lower sheaths. 1 
32. Pappophoeum Schreb. 
Spikelets 2 to 5 flowered, the upper reduced, the rachilla disarticu- 
lating above the glumes but not between the florets, the internodes 
very short ; glumes nearly equal, keeled, thin-membranaceous, as long 
as or longer than the body of the florets, 1 to several nerved, acute; 
lemmas rounded on the back, firm, obscurely many nerved, dissected 
above into numerous spreading scabrous or plumose awns, the florets 
falling together, the awns of all forming a pappuslike crown ; palea 
as long as the body of the lemma, 2-nerved, the nerves near the 
margin. 
Erect, cespitose perennials, with narrow or spikelike tawny or 
purplish panicles. Species 20, in the dry parts of the Old World, in 
Australia, and from Texas to Argentina; 3 species in the United 
States, from Texas to Arizona. 
Type species: Pappophorum alopecuraideum Vahl. 
Pappophorum Schreb. ; Vahl, Symb. Bot. 3 : 10. 1794. Only one species de- 
scribed. 
Enneapogon Desv. ; Beauv., Ess. Agrost. 81, pi. 16, f. 11. 1812. Beauvois men- 
tions Enneapogon desvauxii, Pappophorum gracile, P. nigricans, P. pallidum, 
and P. purpurascens. The first one, being figured, is selected as the type. 
Polyrhaphis (Trin.) Lindl., Veg. Kingd. 115. 1847. Based on Pappophorum, 
section Polyrhaphis Trin., under which a single species, P. alopecuroides Vahl, 
is included. 
Pappophorum hicolor Fourn., with purplish, rather loose panicles, 
is found in southern and western Texas ; P. vaginatum Buckl. (fig. 41) , 
with pale, slender, spikelike panicles, and P. wrightii S. Wats. (fig. 
42), with plumbeous short spikelike panicles and 9-nCrved lemma, the 
nerves extending into 9 equal plumose awns, are found from western 
Texas to southern Arizona. Pappophorum wrightii produces cleis- 
togamous spikelets in the lower sheaths. The cleistogenes are larger 
than the normal florets, but the awns are almost wanting. As is the 
1 Chase, Amer. Journ. Bot. 5: 256. 1918. 
