MANUAL OF THE GRASSES OF THE UNITED STATES 



227 



Figure 303. — Pappophorurn bicolor, X 1. (Griffiths 

 6291, Tex.) 



40. ENNEAP0GON Desv. ex Beauv. 



(Included in Pappophorurn Schreb. in Man- 

 ual, ed. 1) 



Spikelets 3-flowered, the first floret 

 fertile, the second smaller, sterile, the 

 third rudimentary; glumes strongly 

 7-nerved; lemmas rounded on the 

 back, firm, the truncate summit bear- 

 ing 9 plumose equal awns; palea a 

 little longer than the body of the 

 lemma, the keels near the margin. 

 Slender tufted perennials, with nar- 

 row feathery panicles. Type species 

 Enneapogon desvauxii Beauv. Name 

 from ennea, nine, and pogon, beard, 

 alluding to the 9 plumose or bearded 

 awns. A single species in America. 



1. Enneapogon desvauxii Beauv. 

 Spike pappusgrass. (Fig. 304.) 

 Culms numerous, slender, decumbent- 

 spreading, 20 to 40 cm. tall, the nodes 

 pubescent; blades flat to subinvolute, 

 about 1 mm. wide; panicle spikelike, 

 gray green or drab, mostly 2 to 5 cm. 

 long, sometimes interrupted below; 

 glumes longer than the body of the 

 lemmas, 7-nerved, acuminate, pubes- 

 cent; lemma of first floret (including 

 awns) 4 to 5 mm. long, the body about 

 1.5 wmm. long, villous, 9-nerved, the 

 awns plumose, except at the apex. 

 % {Pappophorurn wrightii S. 



Wats.) 11 — Dry plains and stony hills, 

 Utah and Texas to Arizona, south to 

 Oaxaca, Peru, Bolivia, and Argentina. 

 Cleistogamous spikelets are produced 

 in the lower sheaths, the cleistogenes 

 larger than the normal florets, but the 

 awns almost wanting. The culms dis- 

 articulate at the lower nodes, carrying 

 the cleistogenes with them. Furnishes 

 a fair proportion of forage on sterile 

 hills. 



41. SCLEROPOGON Phil. 



Plants monoecious or dioecious. 

 Staminate spikelets several-flowered, 

 pale, the rachilla not disarticulating; 

 glumes about equal, membranaceous, 

 long-acuminate, 1-nerved or obscurely 

 3-nerved, nearly as long as the first 

 lemma; lemmas similar to the glumes, 

 somewhat distant, 3-nerved or ob- 

 scurely 5-nerved, mucronate; palea 

 obtuse, shorter than the lemma. Pis- 

 tillate spikelets subtended by a nar- 

 row bract on the pedicel, several- 

 flowered, the upper florets reduced to 

 awns, the rachilla disarticulating 

 above the glumes but not separating 

 between the florets or only tardily so ; 

 glumes acuminate, 3-nerved, with a 

 few fine additional nerves, the first 

 about half as long as the second ; lem- 

 mas narrow, 3-nerved, the nerves ex- 

 tending into slender, scabrous, spread- 

 ing awns, the florets falling together, 

 forming a cylindric many-awned fruit, 

 the lowest floret with a sharp-bearded 

 callus as in Aristida; palea narrow, 

 the 2 nerves near the margin, pro- 

 duced into short awns. Stoloniferous 

 perennial, with short flexuous blades 

 and narrow few-flowered racemes or 

 simple panicles, the staminate and 

 pistillate panicles strikingly different 

 in appearance. Staminate and pistil- 

 late panicles may occur on the same 

 plant, or rarely the 2 kinds of spikelets 

 may be found in the same panicle. It 

 may be that the seedlings produce 2 

 kinds of branches, each kind then re- 



11 For an account of the genus and the 

 identity of this species, see Chase, A., Ma- 

 drona 7 : 187-189. 1946. 



