AGROSTIDE.E. 211 



A slender diffuse tiU'tcd aiimial, much brancliet-l at the base, 30— 

 75 cm. liigli. Culms compressed, the upper node 0-10 cm. from 

 the roots. Slieaths 2 in number, the lower loose ; ligule very short, 

 slightly ciliate; blades flat or involute, slender, 6-10 cm. long. 

 Panicles simple, spikelike, G-10 em. long, rays single or in twos 

 and threes, the longest 2.5 cm. long, bearing 5-7 sessile diverging 

 clusters, each of 3-5 spikelets ; the pedicels and apex of the empty 

 glumes usually containing a few hairs. Empty glumes narrowly 

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

 short awn, first glume (wanting in most spikelets) 7-8 mm. long, 

 second 5-6 mm. long; floret hispid on the back and near the 

 margins, ver}^ gradually tapering into a short, stout, slightly- 

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



Mexico, Palmer 1084. 



33. A. scabra Kunth, Rev. Gram. 1:63 (1829). Sfreptuchne 

 scabra H. B. K. Nov. Gen. et Sp. 1:124, t. 40 (1815). Oiiacline 

 srabra Fourn. Mex. PI. Enum. Gram. 80 (1886). Probably also A. 

 tenuis Kunth, Streptachne tenuis H. B. K., Ortachne tenuis 

 Fourn. 



Perennial; culms erect, simple, terete, 60-100 or more cm. 

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

 mostly longer than the interuodes: ligule very short, ciliate; blades 

 ascending, loosely involute, 30-60 cm. long, 2-4 mm. wide, sca- 

 brous above and on the margins, pilose near the base, scabrid or 

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

 diffuse, 30-60 cm. long, rays in twos or threes, scabrous, trique- 

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

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

 glumes tinged with jjurple, subequal, 8-13 mm. long, linear, 

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

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

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

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



Florida, Garber, Curfiss 'S4:'31; Arizona, Toianei/ 7oG; Mexico, 

 Palmer 115, 161. Pringh 387, 3776. 



46. (109). Stipa L. Sp. PI. 78 (1753). Jamva Ruiz & Pav. 



