24 Flora of the Palotise Region 



B. emcaeformis Host. Perennial, the culms stout, 60-90 cm. tall, glab- 

 rous throughout: leaf blades 10-30 cm. long, 6-10 mm. wide, scabrous, the 

 loose sheaths exceeding the internodes: panicle narrow, 10-30 cm. long, the 

 densely flowered branches mostly solitary and erect: spikelets nearly orbic- 

 ular, flattened, 2 mm. long. In shallow water or very moist places. 



41. ERAGROSTIS. 



Inflorescence a contracted or open panicle: spikelets many-flow- 

 ered, more or less flattened, rarely dioecious: empty glumes un- 

 equal, shorter than the flowering glumes, keeled, 1 -nerved: flow- 

 ering glumes membranous, keeled, 3-nerved, awnless;palet shorter 

 than the flowering glumes, prominently 2-nervedor 2 -keeled, usu- 

 ally persisting on the rachilla after the flowering glume has fallen: 

 grain free, loosely enclosed in the flowering glume and palet. 



Culms erect: leaves 2-12 cm. long. E. EUTESCEX.s. 



Culms prostrate: leaves 2-3 cm. long. E. REPTANS. 



E. lutescens Scrib. Culms tufted, erect, 10-30 cm. high, branched near 

 the base: leaf blades 2-12 cm. long, 2-4 mm. wide, scabrous above: panicle 

 silvery green, narrow, 5-10 cm. long, the branches ascending, naked below: 

 spikelets oblong, 4-7 mm. long, usually 10-12 flowered. Very rare, on the 

 sandy banks of Snake River near Almota. 



E. reptans Nees. Culms prostrate, creeping, much branched from the 

 base, forming dense circular mats: leaf blades 2-3 cm. long, somewhat pub- 

 escent; sheaths loose, inflated, hairy: panicles very numerous, pale green, 

 dense, 2-4 cm. long, usually with their bases included in the uppermost 

 sheaths: spikelets oblong, 4-7 mm. long. Banks of Snake River, common. 



42. EATONIA. 



Panicles usually contracted: spikelets 2-flowered; the rachilla 

 extending beyond the flowers: empty glumes shorter than the 

 spikelet; the lower linear, acute, i-nerved; the upper much broader, 

 3-nerved, obtuse or rounded at the apex, or sometimes acute, the 

 margins scarious: flowering glumes narrower, generally obtuse, 

 1 -3-nerved, awnless; palet narrow, 2-nerved: grain free, loosely en- 

 closed in the scale and palet. 



Panicle dense, erect: flowering glume obtuse. E. obtt'.sata. 



Panicle loose, usually nodding: flowering glume acutish. 



E. PEXXSYEVANICA. 



E. Obtusata Gray. Somewhat tufted, perennial, .6-1 m. tall, the culms 

 smooth: leaf blades flat, scabrous, 10-15 cm. long, 3-5 mm. wide: panicle 

 erect, narrow, 5-12 cm. long, pale green, the branches short and densely 

 flowered: flowering glnme narrowly obovate, obtuse. Rather rare, on sandy 

 bars of Snake River. 



E. pennsylvanica Gray. Culms 3-90 cm. tall, glabrous: leaf blades 6-15 

 cm. long: panicle slender, 8-15 cm. long, usually loose and nodding, the 

 branches 3-7 cm. long: spikelets about 3 cm. long, usually numerous: flow- 

 ering glume narrow, acutish. Near Steptoe Butte. 



