54 PANICACE^, 



of peduncle, rachis, and pedicels clothed with soft hairs nearly 1 

 cm. long. Sessile spikelet linear-lanceolate, 4 mm. long. Spikelet 

 like that of A. Virginicus L. Pedicel 4 mm. long, bearing a very 

 short rudimentary spikelet. It has the general appearance of 

 A. {(irgenteus Ell.) argyreus Schultz, Curtiss 3637. 



The plant seen is owned by F. L. Scribner, Coll. by A. P. 

 Garber in 1877 in Miami, Fla., distributed as A. argenteus Ell. 

 Marked "teste E. Hackel." 



Florida, Curtiss 3639, distributed as A. macrourus Michx. 

 var. viridis Chapm. ined. 



It is well branched, and too near A. Virginicus L. Perhaps 

 my specimens are not genuine. 



21. A. Hallii Hack. Sitzb. Akad. AVien. 89 : 127 (1884). 



Plant glaucous, smooth, excepting the margins of the blades. 

 Culms rather stout. 80-120 cm. high, usually branching once or 

 more near the top. Ligule 2-3 mm. long; blades of the culm 15 

 cm. long, 4 mm. wide, the upper reduced to mere points. Spikes 

 2, at the apex of the culm and branches, 5-9 cm. long, protruding a 

 little above the leaves; rachis and pedicels pubescent on the edges, 

 the hairs shorter than the spikelets. First glume of sessile spikelet 

 firm, lanceolate, 11 mm. long, a vertical groove on the back, mar- 

 gins ill volute, 6-nerved; second curved towards the flower, ovate- 

 lanceolate when s^iread, 10 mm. long, compressed-keeled, a faint 

 nerve on each margin; third shorter, hyaline, fourth hyaline, bifid, 

 bearing a twisted awn over 1 cm. long; palea hyaline, 6 mm. long, 

 1.5 mm. wide. Lodicules truncate, 1 mm. long. The first glume 

 of the pedicellate spikelets lanceolate, scabrous, margins involute, 10 

 mm. long. 9-nerved; second a little shorter, 3-nerved; third and 

 fourth hyaline, containing rudiments of stamens and pistils. 



Colorado, Vasey ; Texas, Nealley. 



Growing from Kansas to Arizona. 



Var. flaveolus Hack. Joints of the spikes with yellow hairs; 

 spikelets 8 mm. long, first and second glumes pilose on the back 

 or outside; the awn of the fourth 2-5 ram. long, scarcely extend- 

 ing above the hairs of the other glumes. E. Hall 651 ; Barhour in 

 1862; Texas, Nealley. 



