566 GKAMINE^. (grass FAMILY.) 



35. BROMUS, L. Brome-Gkass. 



Grasses with flat leaves, and long-stalked spikelets in loose panicles. Spike, 

 lets large, 3 - manj-flowcred. Glumes membranaceous, unequal, commonly 

 keeled. Lower palea usually awned under the apex, convex on the back, about 

 7-nerved at the base. Stamens 3. Grain flattened and grooved on the inner 

 face, and adherent to the upper palea. 



1. B. ciliatUS, L., var. purgans, Gray. Perennial; panicle diff'use, the 

 slender drooping branches mostly by pairs ; spikelets lanceolate after flowering, 

 10- 12-flowered ; lower glume 1 -nerved, the upper 3-nerved ; lower palea convex 

 on the back, 7-nerved, hairy, about as long as the awn ; culms 2° - 4° high ; 

 leaves and sheaths smooth or downy. — River-banks and rich soil, Florida, and 

 northward. June. 



2. B. secalinus, L. (Cheat or Chess.) Annual; panicle spreading, 

 with clustered, at length drooping branches; spikelets (j'-l'long) 8-10-flow- 

 ered, oblong-ovate ; lower glume .5-nerved, the upper 7-nerved ; palese smooth, 

 the lower one convex, 7-nerved, awnless or short-awned ; culms l°-2° high; 

 leaves and sheaths smootli or downy. — Grain-fields, &c. Introduced. 



36. UNIOLA, L. 



Tough perennial grasses, with erect culms, from creeping rootstocks, and 

 mostly broad, flat many-flowered spikelets, in erect or drooping panicles, with 

 one or more of the lower flowers glume-like and neutral, and the upper imper- 

 fect. Glumes lanceolate, compressed-keeled. Lower palea rather rigid, strongly 

 compressed-keeled, nerved, awnless, much larger than the 2-keeled upper one. 

 Grain free. Stamens 1-3. 



* Spikelets long-pedicelled, drooping : flowers appressed. 



1. U. latifolia, Michx. Culms 2° -3° high ; leaves flat, lanceolate i^'- 

 1' wide) ; panicle loose, drooping; spikelets green, oblong, acute, 10- 15-flow- 

 ered ; lower palea one third longer than the upper, fringed on the keel, acutish ; 

 stamen 1. — Banks of rivers, Florida, and northward. July and Aug. — Spike- 

 lets I2''-15" long. 



2. U. paniculata, L. Culms stout, 3° - 5° high ; leaves very long, rigid, 

 soon convolute ; panicle crowded, drooping ; spikelets whitish, oblong-ovate, 

 about r2-flowered ; paleae equal, the lower one notched at the apex, serrulate on 

 the keel ; stamens 3. — Drifting sands along the coast. West Florida, and north- 

 ward. July and Aug. — Plant pale. Leaves 2° - 4° long. 



* * Spikelets sessile or nearly so, erect : flowers at length spreading. 



3. U. gracilis, Michx. Panicle long and slender, with the branches ap- 

 pressed ; spikelets small (2" -3"), wedge-shaped, 4-6-flowered; lower palea 

 longer than the upper one, smooth on the keel, obtuse ; stamen 1. — Rich damp 

 soil, Florida, and northward. July and Aug. — Culms slender, mostly erect, 

 2° - 4° long. Leaves 2" - 6'' wide. Sheaths smooth or downy. 



