37 



Mexican boundary, 2000 Mearns 1893; no locality, 728 Palmer 1896; Oaxaca, 344 



Conzatti & Gonzalez 1897. 

 Readily distinguished from the type by its larger size and elongated, spreading 



branches of the panicle. 

 CH^TOCHIiOA GRISEBACHII MEXICANA var. nov. Seiarin mexicana 



Schaffner in Herb. 

 A denseh' caespitose form, 6 to 10 cm. high, with interrupted panicles 1 to 3 cm. 



long and short leaves 2 to 3 



cm. in length. Spikelets as 



in the type. 

 San Luis Potosi, 1044 Schaffner 



1876; Schaffner, Sept., 1877. 



i Flowering glume finely trans- 

 versely lurlnkled. 

 = Panicle obtuse at the apex. 



26. CHJETOCHLOA POLY- 

 STACHYA (Scheele) n. 

 Gomb. Setaria jwlystachya 

 Scheele, Linnaea 22: 339 



(1849). (Fig. 22.) 

 A stout, erect perennial, 6 to 12 

 dm. high, with compressed 

 culms, lanceolate leaves, and 

 loose elongated panicles 1 to 

 2 dm. in length. Culms cylin- 

 drical or subcompressed, 

 branching at the base, genic- 

 ulate, glabrous or slightly 

 scabrous below the nodes 

 and panicle; nodes brown, 

 bearded with short appressed 

 hairs; sheaths striate, gla- 

 brous or slightly pubescent 

 above, bearded at the apex, 

 margins ciliate, the lower 

 ones subcompressed, more or 

 less scabrous on the keel; 

 ligule short, ciliate-f ringed; 

 leaf-l)ladesl.5 to 3 dm. long, 

 1.5 to 2 cm. wide, abruptly 

 narrowed at the base, acumi- 

 nate, scabrous on both sides 

 and especially so on the car- 

 tilaginous margins, the lower 



ones often more or less strigose-pubescent, midvein prominent below, becoming 

 obsolete above. Panicle pale green, lanceolate, lax, 1.5 to 2.5 dm. long, 1.5 to 3 

 cm. in diameter; rachis angular, pilose, branches slender, 1.5 to 3 cm. long, erect- 

 spreading, much exceeding their internodes; setse solitary, 8 to 12 mm. long, green, 

 slender, flexuous, antrorsely scabrous. Spikelets narrowly ovate, acute, 2 mm. 

 long; first, glume about one-third as long as the spikelet, slightly inflated, trian- 

 gular-cordate, acute, 3-nerved; second glume two-thirds as long as the spikelet, 

 acute, 5-nerved, the midnerve excurrent, the lateral ones anastomosing with it; 

 third glume equaling the flowering glume, slightly sulcate, acute, 5-nerved, sub- 



FlG. 22.— Ohcetochloa polystachya: a, spikelet showing the 

 seta; 6, c, views of the spikelet ; d, tioweriug glume, dorsal 

 view. 



