GRAMINEAE. 



Vol. I. 



i. Sphenopholis obtusata (Michx.) 



Scribn. Early Bunch-grass. Fig. 



586. 



Aira obtusata Michx. Fl. Bor. Am. 1 : 62. 1803. 

 Eatonia obtusata A. Gray, Man. Ed. 2, 558. 1856. 

 Eatonia pubescens Scribn'. & Merr. Circ. U. S. 



Dep. Agr. Agrost. 27 : 6. 1900. 

 E. robusta Rydb. Bull. Torr. Club 32 : 602. 1903. 

 6 1 . obtusata Scribn, Rhodora 8: 144. 1906. 



Culms i°-2i° tall, erect, simple, often stout, 

 smooth and glabrous. Sheaths shorter than 

 the internodes, usually more or less rough, 

 sometimes pubescent; ligule ¥'-i" long; blades 

 1 '-9' long, 1 "-4" wide, scabrous; panicle 2'-6' 

 in length, dense and generally spike-like, strict, 

 the branches ii' long or less, erect; spikelets 

 crowded, ii"-i4" long; empty scales unequal, 

 often purplish, the first narrow, shorter than 

 and about one-sixth as wide as the obtuse or 

 almost truncate second one; flowering scales 

 narrow, obtuse, l"-i" long. 



In dry soil, Maine to Saskatchewan, Florida and 

 Arizona. Prairie-grass. June-Aug. 



2. Sphenopholis pallens (Spreng.) Scribn. 

 Tall Eaton's Grass. Fig. 587. 



Aira pallens Spreng. Fl. Hal. Mant. 33. 1807. 

 Eatonia Pennsylvania a A. Gray, Man, Ed. 2, 558, in 



part. 1856. 

 5. pallens Scribn. Rhodora 8: 145. 1906. 



Usually glabrous, culms l°-3° tall, erect, simple, 

 slender, smooth. Sheaths shorter than the inter- 

 nodes; ligule I" long; blades 2Y-7' long, i"~z" 

 wide, rough ; panicle 3'-7' in length, contracted, 

 often nodding, lax, its branches i'-2i' long; 

 spikelets ii"-lf" long, usually numerous, some- 

 what crowded and appressed to the branches ; 

 empty scales unequal, the first narrow, shorter 

 than and about one-sixth as broad as the obtuse 

 or abruptly acute second one, which is smooth, 

 or somewhat rough on the keel ; flowering scales 

 narrow, acute, \\" long, rarely awned. 



In hilly woods or moist soil, Newfoundland to 

 British Columbia, Georgia and Texas. June-July. 



3. Sphenopholis nitida (Spreng.) Scribn. 

 Slender Eaton's-grass. Fig. 588. 



Aira nitida Spreng. Fl. Hal. Mant. 32. 1807. 

 Eatonia Dudleyi Vasey, Coult. Bot. Gaz. 11: 116. 1886. 

 Eatonia nitida Nash, Bull. Torr. Club 22: 511. 1895. 

 E. glabra Nash, in Britt. Man. 1043. 1901. 

 S. nitida Scribn. Rhodora 8: 144. 1906. 



Glabrous, culms i°-2° tall, erect, very slender, 

 smooth. Sheaths shorter than the internodes, gen- 

 erally pubescent; ligule I" long; blades ¥-3' long, 

 1" wide or less, often pubescent, the uppermost very 

 short; panicle 2'-6' in length, lax, the branches 

 spreading at flowering time, afterwards erect, i'-2i' 

 long; spikelets not crowded, i4" long; empty scales 

 smooth, the first about one-third as wide as and 

 equalling the second, which is obtuse or almost trun- 

 cate, often apiculate ; flowering scales narrow, i"-ii" 

 long, obtuse or acutish, smooth. 



In dry woods, Vermont to Michigan, Georgia and Mis- 

 sissippi. May-June. 



