WOOTON AND STANDLEY FLORA OF NEW MEXICO. 75 



New Mexico: Tunitcha Mountains; Coolidge; Horsethief Canyon; Albuquerque; 

 Johnsons Mesa; Rio Pueblo; Trout Spring; Raton Mountains; Chama; Sandia Moun- 

 tains; Fort Bayard; Mangas Springs; Socorro. Open slopes, in the Transition and 

 Canadian zones. 



32. SPOROBOLTJS R. Br. Dropseed. 



Annuals or perennials with small spikelets; spikelets 1-flowered, pedicellate, in 

 narrow or broad panicles; glumes rounded or slightly keeled, awnless, obscurely 

 nerved or nerveless, usually unequal; lemma equaling or exceeding the glumes, not 

 awned; palea as long as the lemma or longer; stamens 3; styles short, distinct. 



KEY TO THE SPECIES. 



Panicles narrow, spikelike. 



Plants tall, robust, 1 meter high, erect \. s. giganteus. 



Plants low, slender, CO cm. high or less, spreading or ascend- 

 ing 2. S. strict us. 



Panicles branched and spreading. 



. Annual, 20 cm. high or less 3. S. confusus. 



Perennials, usually more than 20 cm. high. 



Plants with long scaly rootstocks; glumes about equal. 

 Panicles 8 cm. long or less; stems rigid although slen- 

 der 4. S. auriculatus. 



Panicles 13 to 20 cm. long; stems weak, often elon- 

 gated 5. S. asperifolius. 



Plants witlmut long scaly rootstocks; glumes very unequal. 

 Sheaths naked or sparingly filiate in the throat. 

 Plants 30 cm. high or less; spikelets long-pedi- 

 cellate; sheaths villous 6. S. texcinus. 



Plauts more than 50 cm. high; spikelets short- 

 pedicellate; sheaths not villous. 

 Plants less than 90 cm. high; panicles open, 

 with comparatively few spikelets; 



glumes nerved 7. S. airoides. 



Plants 100 to ISO cm. high; panicles rather 

 narrow, with very numerous spikelel 



glumes not nerved s. .S'. v/rightii. 



Sheaths with a conspicuous tuft of hairs in the throat. 

 Sheaths pubescent; leaf blades divergent; pani- 

 cles 8 cm. long or less; plants not nil .re than 



30 cm. high, slender it. S. )i<iil/<ui. 



Sheaths almost it quite glabrous; leaf blades aol 

 divergent; panicles 15 to 30 cm. long or 



mure; plant mostly (ill cm. high or more. 



stout. 

 Panicles exserted, spreading, sometimes 

 somewhat nodding, the lower branches 



about as long as the upper ones 12. 8.JL cuo 



Panicle mo I ly included in the sheaths, 

 ran-l, ii at all spreading, the lower 

 branches longer than the upper. 

 Lemmas about equaling the glumi 



acute to obtuse, less than 2 nun. 



long 10. S. eryptandrui. 



I .. mma i mu< h longer than glumes, long 



.e mi. in. il-. . l"i. nun. I'll" II 



