WOOTON AND STANDLEY FLOEA OF NEW MEXICO. 65 



New Mexico: Twenty-five miles south of Gallup; Clayton; Cross L Ranch; Albu- 

 querque; Suwanee; Socorro; Texline; Mogollon Mountains; Tortugas Mountain; 

 Buchanan; Knowles; Arroyo Ranch; east of Carlsbad; Mesilla. Dry plains and hills, 

 in the Lower and Upper Sonoran zones. 



The subspecies laxiflora is a form with very slender curved pedicels and is probably 

 the same as A. subuniflora Nash, 1 the type of which we have not seen. It occurs 

 wherever the type grows, and may be recognized by the fewer spikelets on very 

 slender curved pedicels and the usually longer awns. 



25. STIPA L. Porcupine grass. 



Tufted perennials with mostly narrow or involute leaves, and terminal, usually 

 open panicles; spikelets 1-flowered; rachilla articulated above the glumes and pro- 

 duced below the lemma into a strong bearded obconical sharp-pointed callus; 

 glumes thin, membranaceous, subequal, acute or bristle-pointed; lemma narrow, sub- 

 coriaceous, closely investing the floret, terminating in a twisted and geniculate simple 

 awn articulated with the apex; grain terete, closely enveloped by the indurated 

 lemma. 



key to the species. 

 Glumes 2 cm. long or more. 



Awns plumose 1. 5. neomexicana . 



Awns not plumose. 



Base of panicle usually included in the sheaths; lemmas 



8 to 12 mm. long 2. S. comata. 



Base of panicle exserted; lemmas more than 12 mm. long. 



Lemmas 12 to 15 mm. long 3. S. tweedyi. 



Lemmas 20 to 25 mm. long 4. S. spartea. 



Glumes 15 mm. long or less. 

 Panicles loose and open. 



Lemmas 4 mm. long or less. 



Awns 60 to 80 mm. long, curled above the joint; lem- 

 mas about 3 mm. long 5. S. tenuissima. 



Awns 15 mm. long or less, not curled; lemmas about 



4 mm. long 6. S. fimbriata. 



Lemmas 6 to 9 mm. long. 



Glumes broad; awns about 25 mm. long 7. S. pringhi. 



Glumes narrow; awns 40 to 50 mm. long 8. 5. eminens. 



Panicles narrow, dense, spikelike. 



Glumes scarious, prominently nerved. 



Awns long-hairy below 9. S. speciosa. 



Awns not long-hairy. 



Lemmas 5 mm. long or less, long-hairy near the 



apex 10. S. lettenih 



Lemmas more than 5 mm. long, equally hairy 



throughout 11 8 vii idula. 



Glumes firm, thick, not prominently nerved. 



Lemmas 4 to 5 mm. long 12. S. minor. 



Lemmas 8 to 10 mm. long. 



Panicles slender; stems l<>v. and Blender; I' ■ 



narrow L3. 8. scribneri. 



Panicles stout and dense; stems tall and stout; 



leaves broad II s ' < 



1 Xash in Small. I'l. Southeast. U. B. im. 1908. The type was collected in New 

 Mexico in 1881, by G. II. Vasey. 



,76°— 15 5 



