29 



l^ Leaves linear-lanceolate, green. 



19. CHiETOCHLOA MACROSTACHYA' (H. B. K.) n. comb. Setaria macros- 



tachya H. B. K. Nov. Gen. & Sp. PL 1: 110 (1815). (Fig. 16.) 

 An erect or ascending perennial, 6 to 12 dm. higli, with rather dense cyhndrical 



panicles and linear-lanceolate leaves 1.5 to 5 dm. in length. Culms rather stout, 



compressed and more or less branched below, striate, scabrous below the nodfes 



and panicle, otherwise smooth; nodes glabrous, sheaths loose, striate, glabrous, 



usually exceeding the inter- 

 nodes, scabrous on the keel, 



bearded at the apex, margins 



ciliate-f ringed; ligule fringed 



with straight white hairs, 3 to 



4 mm. long; leaf -blades rigid, 



linear-lanceolate, scarcely nar- 

 rowed at the base, gradually 



tapering to the long acuminate 



apex, 1 to 1.5 cm. Avide, sca- 

 brous on both sides or rarely 



nearly smooth, generally with 



a few long white hairs toward 



the base, midvein prominent 



throughout. Panicle pale green, 



strict, thyrsoid, cylindrical, 



usually tapering to the apex, 1 



to 3 dm. long, 1 to 2 cm. in 



diameter ; common axis angular, 



sparingly villous; branches 



short, contiguous, densely 



flowered, erect, exceeding their 



internodes, the lower generally 



slightly remote; setae solitary 



or in pairs, slender, flexuous, 



antrorsely scabrous, 1 to 2 cm. 



in length. Spikelets ovate- 

 globose, about 2 mm. long, 



acute; first glume one-third to 



one-half as long as the spikelet, 



broadly ovate, acute, inflated, 



and inclosing the base of the 



spikelet, 3 to 5 nerved; second 



glume two-thirds to three- 

 fourths as long as the spikelet, 

 broadly ovate, obtuse, apicu- 

 late, 5 to 7 nerved; third glume 

 equaling the spikelet, slightly inclosing it by its infolded margins, sulcate, 

 5-nerved, subtending a lanceolate, hyaline palea about its own length; flowering 

 glume strongly convex, apiculate, striate, and rather prominently transversely 

 undulate-rugose, especially below, the inclosed palea equaling it in length, striate, 

 nearly plane. 

 Texas to Mexico and South America. 



Fni.l6.—C luelochloa macrostaehya: a, spikekt sbuuiug 

 the seta ; 6, c, views of the spikelet ; d, flowering glume, 

 dorsal view. 



^ CH.ETOCHLOA AuSTRALIENSIS Sp. nOV. , j -lit; 



A Stout, erect, or ascending grass, with lancecjlate leaves and rather dense panicles l.D 

 to 2 dm. long. Culms glabrous, except below the nodes and panicles; ligule 



