GRASSES OF OHIO 299 



Tribe, Agrostideae. Bent-grass Tribe. 



Grasses with more or less laterally compressed spikelets jointed 

 above the empty glumes and arranged in panicles or racemes; spikelets 

 i-Howered, the rachilla sometimes prolonged behind the palet into a 



naked or plumose bristle. 



e*?. Sporobolus R. Br. Rush-grass. Dropseed. 



Perennial or rarely annual grasses with flat or convolute leaves 



and open or contracted panicles, our species with a peculiar constric- 

 tion about the middle of the leaf blade. Spikelets usually small, 1- 

 flowered, awnless; empty glumes usually unequal, membranous; 

 lemma 1-nerved. equaling or longer than the empty ones; palet 

 2-nerved, often splitting at maturity; grain. free, readily falling from 

 the spikelet. 



1. Panicle contracted. 2 



1. Panicle open, its branches spreading; steins tufted; perennials. 5 



2. Lemma pubescent. 3 



2. Lemma glabrous. 4 



3. Panicle 2-5 in. long, its branches 1-2 in. long; palet long-acuminate: perennial. 



S. eland estinus. 



3. Panicle 1-2 in. long, its branches l / 2 in. long or less: palet long-acute: annual. 



S. vaginaeflorus. 



4. Panicle 3-10 in. long: sheaths cylindnc; palet obtuse: perennial. S. aster. 



4. Panicle 1-2/1 in. long, sheaths inflated; palet acute; annual. S. neglectus. 



5. Spikelets % in. long or less ; empty glumes ovate to lanceolate, leaf sheaths 

 densely pilose at the throat. S. cryptandrus. 



5. Spikelets nearly 54 i"- long; outer empty glumes subulate, leaf sheaths glabrous 

 or sparingly pilose at the summit. 5". heterolepis. 



1. Sporobolus asper (Mx.) Kunth. Longleaf Rush-grass. A 

 perennial grass with stout, erect, simple or occasionally branched 

 stems, \yi-Zy 2 ft. high and terminal linear panicles, partly included 

 in the inflated upper sheath. Lemma glabrous, acutish or obtuse. 



In dry sandy soil. Aug.. Sept. Lake, Erie, Franklin. 



2. Sporobolus vaginaeflorus Torr. Sheathed Rush-grass. An 

 annual grass with tufted, slender stems, 'A-IK' ft. high, and numerous 

 panicles partly included in the inflated sheath, the terminal one 

 exserted. Lemma acuminate, scabrous, shorter than the sharp- 

 pointed palet. 



In dry soil. Aug.. Sept. Auglaize. Madison. Warren, Vinton, 

 Athens. 



3. Sporobolus neglectus Nash. Small Rush-grass. An annual 

 grass with erect slender often much branched, usually decumbent 



