GRASSES OF OHIO 287 



Tribe, Aveneae. ( >ats Tribe. 



Grasses with laterally compressed, 2-several-ftowered spikelets, 

 usually jointed above the empty glumes and arranged in panicles; empty 

 glumes usually longer than the flowering glumes; one or more of the 

 palets usually awned on the back or from between the 2-toothed apex. 



15. Danthonia DC. Wild-oat-grass. 



Mostly erect perennials with narrow leaves and small terminal 

 contracted or open panicles. Spikelets 3-many-flowered, the upper- 

 most staminate or vestigial ; rachilla pubescent, extending beyond 

 the flowers ; empty glumes keeled, acute, subequal, much longer than 

 the lemmas, usually exceeding the uppermost flower: lemmas 

 rounded on the back. 2-toothed, with a flat, twisted and bent awn 

 between the teeth ; palet hyaline. 2-keeled : grain free. 



1. Teeth of the lemma triangular, not awn-pointed; leaves of the stem short. 



D. spica ta. 

 1. Teeth of the lemma aristate; leaves of the stem elongated. D. compressa. 



1. Danthonia spicata (L.) Beauv. Common Wild-oat-grass. A 

 grass with terete stems, \-2 l / 2 ft. high, with involute leaves, and with 

 a few-flowered panicle, often reduced to a raceme, the few short 

 branches erect or ascending. Spikelets 5-8-flowered, on short stiff 

 pedicels ; lemma sparsely clothed with stiff hairs, broadly oblong, 

 its teeth triangular, the bent awn longer than the body of the lemma. 



In dry or rocky soil. June-August. General. 



2. Danthonia compressa Aust. Flattened Wild-oat-grass. A 

 grass with simple, erect, slender, flattened stems, often decumbent 

 at the base, 1^2-3 ft. high, and an open panicle the lower branches 

 generally spreading. Spikelets 5-10-flowered ; lemma oblong, with 

 aristate teeth, a ring of short hairs at the base, and an erect or some- 

 what bent and twisted awn. 



In dry woods. July-September. Portage County. 



16. Arrhenatherum Beauv. Oat-grass. 



Tall perennials with flat leaf-blades and long narrow panicles. 

 Spikelets 2-flowered, the lower staminate, the upper bisporangiate, 

 rachilla extending beyond the flowers: empty glumes thin-mem- 

 branous, keeled, acute, unequal: lemmas rigid. 5-7-nerved, the first 

 bearing a long bent, twisted, dorsal awn arising below the middle, 

 the second unawned : palet hyaline, 2-keeled: grain free, ovoid. 



1. Arrhenatherum elatius (L.) Beauv. Oat-grass. A gr - 

 with a simple erect stem, 2-4 ft. high, and a narrow, shining, pale or 



