GRAMINEJE. (GRASS FAMILY.) 555 



long as the middle one. — Dry pine barrens, Florida to North Carolina. July 

 and Aug. — Lower palea spotted with purple. 

 4- 2. A. purpurascens, Poir. Culms (l£°-2° high) slender, sparingly 

 branched; sheaths smooth; glumes sometimes nearly equal, purple; lower 

 palea (8" long) V-J as long a.s the nearly equal awns. — Dry soil, Florida, 

 and northward. Aug. — Panicle slender, 1° lung, with the branches appressed. 



* * Glumes equal, or the upper one longer. 



3. A. gracilis, Ell. Culms much branched at the base, very slender; 

 leaves rl at ; panicle very narrow, with distant appressed branches; middle awn 

 rather longer than the rough and spotted lower palea, the lateral ones much 

 shorter; glumes nearly equal. — Dry gravelly soil, Florida to North Carolina. 

 Aug. — Culms (with the panicle) 0'- 12' high. Spikelets purple. 



4. A. virgata, Trin. Culms (2° -3° high) branched near the base; leaves 

 flat, rigid ; panicles (1° long) loose ; glumes nearly equal ; middle awn spread- 

 ing, twiee as long as the crcet lateral ones, and four times the length of the short 

 (2" long) lower palea. — Dry soil, Florida to North Carolina. 



Var >. palustris. Every way larger (3° -5° high), with the panicle 1^°- 

 2^° long, and the straight awns nearly equal. — Margins of pine-barren ponds, 

 West Florida. Aug. and Sept. 



5. A. Striata, Michx. Culms (2° -3° high) tufted, simple, straight; leaves 

 chiefly radical, filiform, involute, rigid, hairy at the base; panicle (1° long) 

 spiked; lateral awns as long as the lower palea, the middle one one third 

 longer. — Dry sandy ridges in the pine barrens, very common. June and July. 

 f- 6. A. dichotoma, Michx. Culms low, fork-branched; leaves filiform, 

 erect; panicle (2'-3' long) spiked ; glumes purple, longer than the palea; and 

 the very short and erect lateral awns, the middle awn shorter than the patese, 

 spreading. — Dry soil in the upper districts. Aug. and Sept. — Culms 6'- 12' 

 high. 



7. A. spieiformis, Ell. Culms simple, rigid, erect (1°-1^° high); 

 leaves rigid, erect, convolute, smooth ; panicle spiked ; glumes much shorter 

 than the long (1') very slender palese, the upper one twice as long as the 

 lower ; awns nearly equal, widely spreading, the middle one as long as the 

 palece. — Low pine barrens, Florida to South Carolina. Aug. and Sept. — 

 Panicles 2' -4' long, at length twisted. 



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

 filiform, convolute; spikelets scattered, single or by pairs, in a simple terminal 

 raceme ; glumes nearly equal, longer than the palea? ; middle awn very long 

 (2'), rather longer than the lateral ones, and 2-3 times the length of the 

 palea;. — South Carolina or Georgia, Nuttall. Sept. 



r 



9. A. tuberculosa, Nutt. Culms rigid, branching (1°-U° high); leaves 

 flat ; glumes nearly equal, longer than the palese, bristle-awned ; awns (2' long) 

 equal, jointed with the palece, twisted below, then widely spreading, several times 

 longer than the palea. — Dry ridges, in the middle districts of Georgia. Sept 

 — Panicle simple. 



