568 GRAMINE.E. (grass FAMILY.) 



40. LOLIUM, L. Darnel. 



Rigid flat-leaved (introduced) grasses, with spiked many-flowered compressed 

 > spikelets, with one edge applied to the jointless rachis. Glume 1, rigid, awnless. 

 Lower palea concave, awnless, or short-awned, herbaceous. Stamens 3. Grain 

 adherent to the upper palea — Spikelets distant on the elongated rachis. 



1. L. temulentum, L. Culm tall (2° high) ; rachis (1° long) flexuous ; 

 glume rigid, many-nerved, longer than the 5-flowered s])ikelet, lower palea awned 

 under the scarious obtuse apex. — Grain-fields, North Carolina. ® 



2. L. arvense, Withering. Culms low (6' -12'); rachis (6' -8' long) 

 straight; glume rigid, many-nerved, shorter than the 8-10-flowered spikelet ; 

 lower palea awnless or short-awned at the scai-ious emarginate apex. — Streets 

 of Apalachicola. July. (I) 



41. AIRA, L. 



Low and slender tufted grasses, with the small 2-flowered stalked spikelets in 

 a loose panicle. Glumes membranaceous, keeled, longer than the flowers. Pa- 

 lese hairy at the base ; the lower one 3 -5-nerved, and awned on the back. Sta- 

 mens 3. Grain oblong, smooth. 



1. A. flexuosa, L. Culms nearly naked, 1°-1^° high; leaves short, 

 bristle-like ; panicle small, capillary, spreading ; lower palea toothed at the apex, 

 much shorter than the slender awn ; grain free. — Mountains of Georgia, and 

 northward. July. IJ. . 



42. TRISETUM, Pers. 



Spikelets 2 - several-flowered. Lower palea compressed-keeled, usually bear- 

 ing a bent awn below the 2-cleft or 2-pointed apex. Otherwise as in Aira. 

 Spikelets in open or spiked panicles. 



1. T. palustre, Torr. Smooth; culms weak (1°- 1^° long) ; leaves flat, 

 linear ; panicle long and narrow, loose ; spikelets 2 - 3-flowered ; the lower 

 flower awnless, the upper with a spreading awn and an awn-like rudiment at the 

 base, or rarely both flowers awnless. (Aira pallens, Muhl. A. triflora. Ell. ?) — 

 Swamps, West Florida to Mississippi, and northward. March and April. — 

 Panicle pale, 4' - 8' long. 



2. T. moUe, Kunth. Soft downy; culms short (6' -8'); panicle (2' -3' 

 long) contracted, dense and spike-like ; spikelets 2-flowercd, the lower palea of 

 both flowers with a spreading a\vn. — Mountains of North Carolina, and north- 

 ward. 



43. DANTHONIA, DC 



Tufted grasses, with racemose or panicled spikelets, and rough or bearded 

 flowers. Spikelets 3 - many-flowered. Glumes nearly equal, membranaceous, 

 longer than the flowers, awnless. Lower palea rigid, concave, many-nerved, 

 bearded below, sharply 2-toothed at the apex, bearing an intermediate awn, 

 which is flattened and twisted near the base. Stamens 3. Grain oblong, free. 



