44 PANICACK.K. 



lute, 7-8-nerve(l, second mombraiious, ciliate-koeled, 4-5-nerved, 

 8 mm. long, third hytilino shorter, fourth G mm. long" hititl over 

 hair its length bearing a bent awn 1"^-17 mm. long. I'edicellato 

 spikelets j)rotruding above tlie hairs. Pedicels tj mm. long bear-ng 

 a lanceolate spikelet a little shorter than itsell* consisting of 'Z empty 

 glumes. 



Texas, Xeallei/j Arizona, Pn'tif/Ic, Leninuhi 0"^5. Tlie latter is 

 owned by F. L. Scribner and mark 'd " teste E. Ilackel." 



\'ar. brevipedicellatus. L blades less than 2 mm. wide. 

 Pedicels 4 mm. long, first glume of the sessile spikelet G-7 mm. 

 long. 



Mexico, J\-i//(/I(' ;5S:5. Distributed as A. hiflijlin'us Kunth. 



Subvar. oligostachyus (C'hapm.) Hack. D. C. Monog. Phan. 6 : 

 372 (1889). A. uliyustachjius Chapm. Fl. S. States, 581 (1800). 



Kachis slender, 5-() cm. long with 10-15 joints. 



Arizona, Priiiule. 



Var. feensis (Fourn.) Hack. D. C. ^lonog. I'lian. : 372 

 (188!)). .1. frrii.sis Fourn. Mex. PI. Enum. (Jram. «",2 (188»;). 

 Sheaths pilose, "iliate; blades scabrid; racemes 5-7 cm. long, 

 slender. 10-12-jointed, apex of the joint 1 mm. broad, loosely i)ilose. 



Arizona. l.i'iiiDuni 21(25. Mexico, Parri/, Pnhticv !Mi(i. 



3. A. brevifolius Sw. Prodr. Fl. Ind. Occ. 2(i (17!i7). Annual: 

 culms 10-100 cui. loug. very slender with filiform llowi'ring 

 branches in twos and threes from nearly all the nodes. Lignle 

 very short: blade contracted at the insertion, green, glabrous, with 

 margins scabrous, spathcs reddish green, glabrous, clavatc. IJacemcs 

 5-10-join;e(K the joints clavatc, 2-toothe(l. about the U'ngth of the 

 sessile spikeU'ts. Sessile spikelet linear-oblong, pah* green: first 

 glume lirni. involute, 2-to<(ilu'd. subconvex on the back, obscurely 

 2-;»-nerv, >I : si-cond glunu' awnless, very acute, 1-nerved: fourth 

 glume divided almost to the base. Anthers 1-1.5 mm. loug. (Jrain 

 liiu^ar. Pedicellate spikelets 1-1.5 mm. long, on |)edici'ls which are 

 us long as the joints of the racemes, first ghnne bearing a slender 

 awn. 



Var. genuinus Hack. 1). V. Monog. IMian. C : 303 (ISS'I). 

 .1. hrcvifdliiiK var. piilla Franch. et Savat. Enum. IM. .lap. 2, (110 



