70 PAXICACE.E. 



Bliort ; bliuU's 1-5 cm. long, involute, bristling at the throat. 

 Spikes dense, 5 cm. long, 5-12 mm. wide. Empty glumes of tlie 

 lateral spikelets 1-5 mm. long, cuneate, obovate; tlio outer slightly 

 longer, with a short hairy awn on one edge below the middle ; 0-!) 

 diverging nerves disai)i)earing below the rounded, searious apex ; 

 the inner with 4 diverging nerves, one excurrent. as a short awn ; 

 floral glume and palea a little shorter, the outer 3-uerved, with 

 the ai)ex obcordate ; palea emarginate. Empty glumes of the ter- 

 minal spikelet narrow, keeled, equal, bearing 5-G bristles ; floral 

 glume and palea of equal length, the former 3-nerved, bifid, 

 mucronate. 



Texas, Uecerchon 1367 ; Arizona, J'ringle in 188-4. 



4. H. Jamesii (Torr.) Heuth. 1. c, Plcuraphis Jamesii Torr. 

 Ann. Lye. N. Y. 1 : U8, i. 10 (1824). 



Culms 25-40 cm. high, slender, branching at base, the nodes 

 pubescent. Ligule oval, laciniate ; blades 1-15 cm. long, appear- 

 ing glaucous, owing to the numerous very small, stitT prickles, con- 

 volute, scabrous, luiiry at the throat. Spikes 5-8 cm. long, often 

 tinged with purple. Lower empty glume of the lateral spikelets 

 6-7 mm. long, awned above the middle, outer side 2-nerved ; ui)per 

 empty glume emarginate. cuspidate, 3-nerved on the outer side, 

 two-nerved on the inner side; floral glume and palea about equal 

 to the empty glumes. Empty glumes of the perfect spikelet 

 keeled, ciliate, cleft nearly to the middle, lateral nerves obscure, 

 3-7 bristles on the back ; floral glume and palea exceeding the 

 empty glumes, the former 3-nerved, unequally bilid, cuspidate, the 

 palea a little shorter, bifid. 



Colorado, Jones 702 ; Xew Mexico, Vascy for U. S. Dept. 

 Agricul. 



Indian Territory, Arizona and southward. 



17. (01). .SooFOOON Heauv. Agrost. 122 (1812) in part. 



.Ff/opof/mi H. & li., Willd. Spec. PI. 4 : 809 (1815). Hi/- 

 monothecinm Lag. Gen. et Sp. Nov. 4 (1810). Schellingia Steud. 

 Flora 33 : 231 (1850). Goat's-ueard Grass. 



Spikelets 1-flowered, in clusters of 2-0, the clusters almost 

 sessile on the peduncle or continuous rachis of the simple secondary 



