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. 
82. SPOROBOLUS R. Br. Dropseep. 
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.....................-- 1. S. giganteus. 
Plants low, slender, 60 cm. high or less, spreading or ascend- 
Ing.... 2.2... e eee eee cee eee eee 2. 8. strictus. 
Panicles branched and spreading. 
Annual, 20 cm. high or less.............0 000000. 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.....--- 2-2-2. eee ee eee eee eee Lecce encase 4. S. auriculatus. 
Panicles 13 to 20 cm. long; stems weak, often elon- 
. gated .........-.2-2- 2022-222 e eee eee eee eee ee 5. S. asperifolius. 
Plants without long scaly rootstocks; glumes very unequal. 
Sheaths naked or sparingly ciliate in the throat. 
Plants 30 cm. high or less; spikelets long-pedi- 
cellate; sheaths villous.................. 6. S. texanus. 
Plants 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 180 cm. high; panicles rather 
narrow, with very numerous spikelets; 
glumes not nerved..........-----.-- 8. S. wrightit. 
Sheaths with a conspicuous tuft of hairs in the throat. 
Sheaths pubescent; leaf blades divergent; pani- 
cles 8 cm. long or less; plants not more than 
30 cm. high, slender...........--.--.---- 9. S. nealleyt. 
Sheaths almost or quite glabrous; leaf blades not 
divergent; panicles 15 to 30 cm. long or 
more; plants mostly 60 cm. high or more, 
stout. 
Panicles exserted, spreading, sometimes 
somewhat nodding, the lower branches 
about as long as the upper ones... .. - 12. S. flecuosus. 
Panicles mostly included in the sheaths, 
rarely if at all spreading, the lower 
branches longer than the upper. 
Lemmas about equaling the glumes, 
acute to obtuse, less than 2 mm. 
long....-...------200-- eee ee eee 10. S. eryptandrus. 
Lemmas much longer than glumes, long- 
acuminate, 5 to 6 mm. long......11. S. asper. 
