602 GRAMINE^E. (GRASS FAMILY.) 



8. A. Oligantha, Michx. Culms 1- 2 high, branched, slender; leaves 

 convolute ; spikelets scattered, single or by pairs, iu a simple terminal raceme , 

 glumes nearly equal, ^'-1'long; middle awn l'-2' long, rather longer than 

 the lateral ones, circular-curved at the base. South Carolina, and westward, 

 rare. Sept. 



9. A. purpurascens, Poir. Culms branching at the base, 1- 2 high; 

 leaves flat, glabrous, like the sheaths ; panicle 1- 1-J long, the branches short 

 and erect; empty glumes unequal, the lower 5" long, the upper shorter and 

 equalling the floret ; middle awn 1' long, spreading. Dry sterile soil, com- 

 mon. August. 



10. A. lanata, Poir. Much like the last, but larger (2 -4 high); leaves 

 scabrous on the upper surface, the sheaths woolly ; branches of the panicle 

 longer, and often spreading. With the preceding, but less common. July - 

 August. 



11. A. palustris, Vasey. Culms 3 -4 high, simple or branching; 

 leaves flat, glabrous ; panicle long ( l - 2) and narrow, purple ; empty glumes 

 \' long, nearly equal ; awns 10" - 16" long, the middle one spreading. (A. vir- 

 gata, var. Flora.) In and around shallow pine barren ponds, West Florida. 

 August - Sept. 



12. A. virgata, Triu. Culms simple, 2-4 high; leaves flat, soon con- 

 volute ; panicle loosely or densely branched, 1 - 1| long ; empty glumes equal, 

 or the lower shorter, 4" long ; awns spreading, 6" long. (A. coudeusata, 

 Flora.) Barren sandy soil, near the coast, Florida to North Carolina. 

 August - Sept. 



13. A. Strieta, Michx. Culms (2-3 high) tufted, simple, straight; 

 leaves chiefly radical, filiform, involute, rigid, hairy at the base; panicle (1 

 long) spiked ; glumes short-awned ; lateral awns as long as the floret, the mid- 

 dle one one third longer. Wet or dry pine barrens, very common. June - 



July. 



w- ** Aicns united above the ylume. 



14. A. spiciformis, Ell. Glabrous; culms 1- 2 high, simple; leaves 

 erect, convolute-filiform ; panicle closely spiked, 3' -5' long; empty glumes 

 long-awned, the upper twice as long as the lower one ; awns united far above 

 the glume, the middle one 1' long, spreading. Low pine barrens in the lower 

 districts. August - Sept. 



2. Awns united above the glume, and jointed with its summit. 



15. A. tuberculosa, Nutt. Annual; culms rigid, branching (1-1-J 

 high) ; leaves flat; glumes nearly equal, bristle-awned ; awns (2' long) equal, 

 twisted below, then widely spreading. Dry ridges in the middle districts of 

 Georgia. Sept. Panicle simple. 



38. MUHLENBERGIA, Schreb. DROP-SEED GRASS. 



Spikelets 1 -flowered. Glumes persistent, pointed or awued, equal, or the 

 lower one smaller. Floret sessile in the glumes, commonly hairy at the base, 

 deciduous with the enclosed grain, its glume 3-nerved and mucronate or awued 

 at the apex. Stamens 3. 





