GRASSES OF OHIO 
307 
a hairy callus at the base, terminating in a simple, strong persistent, 
bent, twisted awn; palet 2-nerved, small; grain narrow, free, tightly 
enclosed in the fruiting lemma. 
1. Stipa spartea Trin. Porcupine-grass. A tall, slender grass 
with erect, simple stems, 2-4 ft. high, with involute leaf blades and 
loose, narrow panicles, finally long-exserted. Empty glumes ac¬ 
uminate into long, slender points, glabrous; lemma brownish, ap- 
pressed-pubescent below with a long, rigid, scabrous, twisted, usually 
bent awn; callus acuminate, very sharp-pointed, densely clothed with 
silky, appressed hairs. The awns are highly hygrometric, and the 
sharp-pointed fruit is injurious to animals, by penetrating the skin. 
On plains, prairies, and sandy places. June, July. Erie County, 
where it occurs on Cedar Point. 
49. Aristida L. Triple-awn-grass. 
Tufted annuals or perennials with narrow leaves and usually 
with loose, narrow panicles. Spikelets 1-flowered; empty glumes 
unequal, narrow, acute or acuminate; lemma somewhat indurated, 
convolute, terminating in a three-branched awn; palet thin, 2-nerved; 
grain elongated, free, tightly enclosed in the lemma. 
1. Awns separate to the base, not articulated to the lemma. 2 
1. Awns united below into a long twisted neck and articulated to the lemma. 
A. tuberculosa. 
2. Lateral awns much shorter than the middle one. 3 
2. Lateral awns not much shorter than the middle one. 4 
3. Middle awn coiled at the base. A. dichotonm. 
3. Middle awn not coiled at the base. A. gracilis. 
4. Outer empty glume 5-7-nerved; annuals. A. oliganfha. 
4. Outer empty glume 1-3 nerved; perennials. A. piirpurascens. 
1. Aristida dichotoma Mx. Poverty-grass. An annual tufted 
grass with wiry much-branched stems, J^-2 ft. high, loose, glabrous 
sheaths, much shorter than the internodes, and narrow, simple, few- 
flowered, spike-like panicles, often reduced to racemes, the lateral 
ones often sessile and partly enclosed in the sheaths. Lemma with 
a horizontal awn, coiled at the base, with the two lateral awns erect 
and very short. 
In dry sandy soil. Aug., Sept. Scioto, Vinton, Eairfield. 
2. Aristida oligantha Mx. Eew-flowered Triple-awn-grass. An 
annual, tufted grass with wiry, branched, erect, solid stems, loose 
sheaths, and few-flowered, lax, spike-like racemes or panicles. Empty 
glumes unequal, awned; lemma scabrous above with three nearly 
equal, divergent awns. 
In dry sterile soil. Aug., Sept. Cuyahoga County. 
