452 POAC'E.E. 



of ilio apex, witli awns projoctiiig botwcon the lobes; ])ak'ii two- 

 tliinlrf us lo)i<^ as its glume, •.'-nerved, with two jirojeetiiig awns; 

 floral glume of lower floret of terminal spikelet like those of the 

 lateral s])ikel<'ts, only a little longer; floral glume of neutral floret 

 of terminal sj)ikelet broadly oval. 4-lobed for half its length or 

 more, witli o ])r()je(!ting awns betwron tlu' lobes: jjalea snudler than 

 in ])istillate florets. Ovary obovate. styles distinct, with long pur- 

 plish hairs on two-thirds of the up]»er poi'tiou. On s/oiiii/Hf/c 

 Kjiih'.s, lateral s])ikelets with 2 florets and a tiiird rudiment. Lower 

 emi)ty ghnnes of lateral sj)ik('lets minute, broadly truncate; of ter- 

 minal s[)iki'li't smaller, narrower. r[»pcr empty glume of lati-i'al 

 flowers 2 mm long, elliptieal-laiiceolate, compressed, inecpiilaterid. 

 1-nerved; of terminal s[»ikelet oval. :>-nei'ved ; floral glume ;3 mm. 

 long, oblong, 4-lobed for one-third of its length, witii awns be- 

 tween the lobes; palea' oblong-lanceolate, as long as their glumes, 

 with two parallel nerves slightly pntjecting. Stanu'ns .'{. 

 There ai'e three siieeies found in Texas and Mexico. 



1. C. erectum Vasey »S: Hack. Uull. Torr. Club. 1 1 : ;5r (18S4) 

 and 14: 100 (ISS;). 



A tufted erect perennial. l.'j-IJO cm. high, stoloniferons. nodes 

 villous; light green, tinged with purjile. Ijigule a ciliate ring; 

 blades of sterile shoots ."i-S cm. long, nari'ow, flat or beeonung 

 involute, slightly hairy on the nuirgins and U])])er surface. Culms 

 simple or branching. S[)ikes about 3 em. long, containing 5-9 

 clusters of spikelets. Sjjikelets of the sterile spike 7 mm. long. 



Texas and Mexico. 



2. C. Mexicanum I'resl. Rel. Tla^nk. 1 : 2U^, t. 4"i (18:U)). 

 Nodes smooth, spikelets of the sterile spikes shortly pubescent, 



4-.") mm. long: very variable and apparently only a variety of C. 

 ererhini V. iS; IF. 



West Texas. Ifanird (i'l. 



',]. C. prostratum I'resl, 1. c. 



Sheaths ciliate at the throat. Lower leaves 1-4 cm. long. u)>- 

 per shorter. S[)ikelets of the sterile s])ikes nearly smooth. ;)-4mm. 

 long. Description inconi})lete for want of abundant material. 



^lexico, P((h>ier 2T0. 



