AUKOSTIDE^. 225 



a. Hairs of floret not dense nor conspicuous (c) 



c. Awn plumose 5 



c. Awn stout, persistent, scarcely as long as the empty 



glumes, curved in one ])laiu', spikelets 5 mm. long, 



panicle 2-5 cm. long (> 



c. Awn deciduous, not over 4 jnm. long, spikelets 4 



mm. long, panicle 4-8 cm. long 7 



c. Awn 10-12 mm. long, spikelets 4 mm. long, panicle 



narrow, 5-8 cm. long 8 



c. Awn 9-16 mm. long, spikelets 4-5 mm. long, panicle 



7-12 cm. long 9 



c. Awn 10-15 cm. long, spikelets 4 mm. long, panicle 



8-12 cm. long 10 



c. Panicle 8-16 cm. long, aAvu deciduous, 5-10 mm. 



long 11 



c. Leaf-blades flat or involute, ligule not ciliate. . . (d) 



d. Panicle 15-20 cm. long, awn 20 mm. long. . .12 



d. Panicle 10-13 cm. long, awn 1.5-2 mm. long. 13 



1. 0. melanocarpa Mulil. Gram. 79(1817). Milium racemosnm 

 Sm. Rees, Cyc. 23 :n. 15 (1819?). Fiptafheriwi nigrvm Torr. 

 El. U. S. 1:79 (1824). Urachne racemosa Trin. Unifl. 1:174: 

 (1824). 



Culms erect, slightly rough, leafy at the top, 60-100 cm. high. 

 Sheaths scabrous, about as long as the internodes; ligule short and 

 bearded; blades flat, lanceolate, not quite smooth, tapering towards 

 each end, 25-30 cm. long, 10-15 mm. wide. Panicle simple, nar- 

 row, scarcely exserted, 12-20 cm. long. Spikelets elliptical, acute, 

 about 7 mm. long, empty glumes subequal, reticulate-veined, 7- 

 nerved; floret with a few appressed hairs, blackish, the awn 1.5-2 

 cm. long. 



Vermont. Pr ingle ; Delawai-e, Canhy ; Ontario, Foivler ; New 

 York, Beal 42 ; Michigan, Clark, 703; Iowa, Hitchcock ; Minne- 

 sota, Holzinger 26*^. 



New England, Delaware, Peunsjdvania to \Yisconsin. 



2. 0. asperifolia [Kich. in] Michx. Fl. Bor. Am. 1:51 (1803). 

 Urachne asperifolia Trin. Unifl. 174 (1828). 



