244 



GRAMINEAE. 



VOL. I. 



i. Sphenopholis obtusata (Michx.) 



Scribn. Early Bunch-grass. Fig. 



586. 



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

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

 Eatonia pubcsccns Scribn. & Merr. Circ. U. S. 



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

 E. robnsta Rydb. Bull. Torr. Club 32: 602. 1905. 

 5". obtusata Scribn, Rhodora 8: 144. 1906. 



Culms i-22 tall, erect, simple, often stout, 

 smooth and glabrous. Sheaths shorter than 

 the internodes, usually more or less rough, 

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

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

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

 the branches ii' long or less, erect; spikelets 

 crowded, ii"-ii" 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, i"-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 pennsylvanica A. Gray, Man, Ed. 2, 558, in 



part. 1856. 

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



Usually glabrous, culms i-3 tall, erect, simple, 

 slender, smooth. Sheaths shorter than the inter- 

 nodes; ligule I" long; blades 2-J'-7' long, i"-3" 

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

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

 spikelets \\"-\\" 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, ii" 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. n : 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, 

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

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

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

 long; spikelets not crowded, i' 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. 



