116 POACEAE 
3. Aristida basiramea Engelm. Stems tufted, rather slender, 2-6 dm. tall, branch- 
ing: leaf-blades 3-15 cm. long, 1.5 mm. wide or less, sometimes sparsely pilose above at 
the base: panicle 3-9 cm. long, the branches erect: spikelets 10-15 mm. long, the first 
scale much shorter than the second, the flowering scale 7-11 mm. long, considerably shorter 
than the second, the lateral awns more or less spreading, usually a little spiral at the base, 
4-2 as long as the central awn which is strongly spiral at the base and with the straight 
portion 10-18 mm. long. 
In dry fields, Manitoba to Illinois, Nebraska and the Indian Territory. Summer and fall. 
4. Aristida simpliciflora Chapm. Stems tufted, 4-6 dm. tall, slender, simple or 
sparingly branched : leaf-blades 3.5-15 cm. long, 1-1.5 mm. wide, flat: panicle 1-2 dm. 
long, its branches short and appressed : spikelets 8-9 mm. long, crowded, the 2 outer scales 
1-nerved, about equal or the first a little the shorter, the flowering scale 5-6 mm. long, the 
central awn 12-15 mm. long, strongly reflexed, the lateral awns ascending, about 3 as 
long and much more slender than the central awn. 
In low pine woods, Florida. Fall. 
5. Aristida Mòhrii Nash. Stems 5-7 dm. tall, simple: leaf-blades 5-12 cm. long, 
1-1.5 mm. wide, those on the innovations hirsute above : panicles 1.5-3-dm. long, simple : 
spikelets 10-12 mm. long, on very short pedicels, appressed, scattered, the 2 outer scales 
1-nerved, the first equalling or often a little exceeding the second, the flowering scale 8-9 
mm. long, the awns of equal thickness, all strongly reflexed, the central one 15-18 mm. 
long, the lateral ones a little shorter. 
On dry sandy pine ridges, Alabama. Fall. 
6. Aristida ramosissima Engelm. Stems tufted, 2-4 dm. tall, slender, branched : 
leaf-blades 4-15 cm. long, 1-1.5 mm. wide, flat: panicle 6-10 em. long, simple, the 
branches very short and bearing a single usually ascending spikelet : spikelets 1.6-2.2 cm. 
long, the 2 outer scales usually awned, the first scale 5-7-nerved, shorter than the 3-nerved 
second, the flowering scale 15-18 mm. long, the central awn strongly reflexed, 2-3 cm. 
long, the lateral awns rigid, erect, 1-2 mm. long. 
In dry ground, Illinois and Missouri to the Indian Territory. Late summer and fall. 
7. Aristida fasciculata Torr. Stems tufted, 5-8 dm. tall, branched : leaf-blades 6 -12 
cm. long, 1-2 mm. wide: panicle 7-20 cm. long, its branches short, in fascicles of 2-4, 
erect or nearly so : spikelets 9-10 mm. long, crowded, the 2 outer scales 1-nerved, the first 
one 3-3 as long as the second, the flowering scale 8-12 mm. long, hispidulous on the keel, 
the callus densely pilose, the awns ascending, the central one 10-17 mm. long, the lateral 
awns 2-$ as long. 
In dry soil, Kansas to California, Texas, Mexico and New Mexico. Fall. 
8. Aristida Fendleriàna Steud. Stems densely tufted, 1.5-2.5 dm. tall, erect, rigid, 
simple: leaf-sheaths smooth, confined to the base of the stem, a tuft of hairs on each side 
at the apex ; blades involute, at least when dry, often curved, 0.5 mm. in diameter, those 
on the stem usually 2, 1.5-5 cm. long, the basal longer: panicle 7-10 cm. long, strict, its 
branches short and appressed and usually bearing but a single spikelet, rarely exceeding 
1.5 em. long, or sometimes the lower ones with 2 spikelets: spikelets 12-15 mm. long, the 
2 outer scales l-nerved, the first scale about 4 as long as the second, the flowering scale 
9-12 mm. long, equalling or a little shorter than the second scale, the awns ascending, the 
central one 2-3.5 cm. long, the lateral ones a little shorter. 
In dry sandy soil, South Dakota to Utah, Texas and New Mexico. Summer and fall. 
9. Aristida subuniflóra Nash. Stems densely tufted, 2.5-3.5 dm. tall, erect, 
simple: leaf-sheaths usually confined to the base of the stem; blades involute, at least 
when dry, usually straight, sometimes curved, those on the stem usually 2, 2-4.5 cm. long, 
the basallonger: paniele 6-13 cm. long, its branches more or less spreading, the larger 
ones 2-3 em. long, bearing 1 or 2 spikelets: spikelets 1.5-2 em. long, the 2 outer scales 
l-nerved, the first about 3 as long as the second, the flowering scale 13-15 mm. long, 
usually a little shorter than the second scale, the awns ascending, the central one 3-5 cm. 
long, the lateral awns a little shorter. ; 
In dry sandy soil, central Texas to New Mexico. Spring and summer. 
10. Aristida Wrightii Nash. Stems tufted, 3.5-5 dm. tall, simple, leafy: leaf- 
blades involute, at least when dry, those on the stem usually 3 or 4, 3-20 cm. long, often 
curved, as are the commonly longer basal ones: panicle 1-2 dm. long, its branches more 
or less spreading, the longer usually bearing 2-4 spikelets: spikelets 12-15 mm. long, 
the 2 outer scales 1-nerved, the first scale about 3 as long as the second, the flowering scale 
10-12 mm. long, usually a little shorter than the second scale, the awns ascending, the 
central one 2.5-3 cm. long, the lateral awns a little shorter. 
In dry sandy soil, Kansas to Texas and New Mexico. Summer and fall. 
