ACiHUSTlDKl-:. 211 



A slendor difTu.se tiil'tt'duiimial. imicli braiiflied tit tho base. 30- 

 75 cm. liigli. ("ulnis t'oniprt'sseil. the upper node 0-10 cm. from 

 tlie roots. Slieutlis '2 in number, tlie lower loose; ligule very short, 

 slightly eiliate; blades flat or involute, sleniier. (J- 10 em. long. 

 Panicles sim])le, s[)ikelike, O-lO cm. long, rays single or in twos 

 and tiirecs. the longest ;.'.") cm. long, bearing T)-! sessile diverging 

 clusters, eacli of 3-5 s])ikelets; the pedicels and a])e.\ of the em])ty 

 glumes usually containing a few hairs. Kmi)ty glumes narrowly 

 linear, 1-nerved, apex acute, obtuse or 2-toothed, with a nnu-ro or 

 short awn. first ghune (wanting in most si)ikelets) 7-S mm. long, 

 second 5-6 mm. long: floret liispid on the back and near the 

 imirgins, very gradually tapering into a short, stout, slightly- 

 curved central awn, the whole 2-3 cm. long; lateral awns obsolete. 



Mexico, Palmer 10H4. 



33. A. Bcabra Kunth, Kev. Gram. 1: (j-i (1820). Shrpfachne 

 scabra H. li. K. Nov. Gen. et Sp. 1: 124, /. 40 (1815). (h-farhne 

 umbra Fourn. Mex. PI. Enum. Gram. SO (IHSG). Pro])ably also J. 

 tentiis Kunth, Streptuchne tenuis II. B. K., Ortacline Ivnids 

 Fourn. 



Perennial; culms erect, simide, terete, 00-100 or more cm. 

 high, scabrid or smooth. Sheaths striate, glabrous or scabrid, 

 mostly longer than the iuternodes; ligule very short, eiliate: blades 

 ascending, loosely involute, 30-(iO cm. long, 2-4 nnn. wide, sca- 

 brous above and on the margins, ])ilose near the base, scaljrid or 

 glabrous below. Panicles little exserted, or the base included, 

 diffuse, 30-00 cm. long, rays in twos or threes, scabrous, tricjue- 

 trous, spreading, the longest 15-30 cm. long, sparingly branched 

 and bearing a few spikelets along the outer third or half. Empty 

 glumes tinged with purple, subequal, S-13 mm. long, linear, 

 acute, short awncd, compressed, 1-nerved, the keel scabrous; floral 

 glume spotted, coriaceous, scabrous, 13-15 mm. long to the tips of 

 the verv short lateral awns, the central awn slender, straight or 

 slightly curved, not twisted, 10-15 mm. long. 



Florida, Garber. r«r//.v.s 3431 : Arizona, 'Joudh'i/ 7oG; Mexico, 

 Fahner 115, 101, Pringle 387, 3770. 



40. (101)). Stipa L. Sp. PI. 78 (1753). Jarava Ruiz & Pav. 



