GRAMINE.E. (GRASS FAMILY.) 601 



37. ARISTIDA, L. WIRE GRASS. 



Slender grasses, with narrow leaves, aud mostly loosely racemose or pan- 

 ic-led inflorescence. Spikelets 1-flowered. Lower glumes membranaceous, 

 mostly unequal, acute or awued, the upper stipitate, coriaceous, involute, 

 triple- (rarely single-) awned. Palet minute. Stamens 1-3. Grain included, 

 free. Awns (when dry) often bent or twisted. 



1. Awn continuous (not jointed with the glume). 

 * Glume single-awned. 



1. A. Floridana, Vasey. Culms simple, 2 high ; leaves long, convolute, 

 bearded at the base; panicle 1 long, loosely branched; glumes equal, the 

 upper truncate; awn compressed, curved. (Streptaclme, Flora.) South 



Florida (Blodgett). 



* * Glume triple-aimed. 



* Lateral awns short and erect. 



2. A. dichotoma, Michx. (POVERTY GRASS.) Culms forking, 6'- 12' 

 high; leaves almost setaceous; panicles simple or compound, 2' -3' long; 

 glumes equal or (in var. Curtissii, Gray) unequal; middle awn spiral below, 

 spreading, the lateral minute. Dry sterile ground ; common. August - 

 Sept. 



3. A. ramosissima, Engelm. Culms much branched, i-H high; 

 panicles few-flowered; lower glumes unequal, 8" -10" long; middle awn 

 coiled below, recurved, the lateral l"-3" long, rarely wanting. West 

 Tennessee (Gattinger). 



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

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

 straight, rather longer than the rough spotted lower glume, the lateral ones 

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

 Carolina. August. Culms 6'- 12' high. 



5. A. scabra, Kunth. Culm scarcely any, the long (H-3) peduncle 

 arising from a creeping rootstock ; leaves radical, setaceously attenuate ; 

 panicle large, diffuse, the branches 2-5 in a cluster; spikelets appressed; 

 glumes awn-pointed, the lower one longer; awns straight, erect, the lateral 

 ones very short ; stamens 2. Sandy coast, Florida. 



t- )- Awns long, equal, or nearly so. 

 M- United at the tip of the glume. 



6. A. simpliciflora, Chapm. Culms filiform, 2 high, forking; leaves 

 flat, smoothish ; racemes simple, straight, 6' -9' long, loosely flowered ; empty 

 glumes 3" long, nearly equal, awn-pointed, the lower one rough on the keel, 

 longer than the floret ; middle awn circular-curved near the base. Damp 

 pine barrens, West Florida. 



7. A. gyrans, Chapm. Culms simple, 1 high; leaves convolute-filiform ; 

 panicle simple, with the branches short, appressed ; empty glumes unequal, 

 the lower 2" long, the upper one a third longer, attenuate ; flowering glume 

 long-stipitate, the awns nearly equal, curved at the base. Keys of Caximbas 

 Bay, South Florida. Oct. 



