GENUS 33. 



GRASS FAMILY. 



179 



2. Aristida Curtissii (A. Gray) Nash. Cur- 

 tiss's Triple-awnecl Grass. Fig. 424. 



A. dichotoma var. Curtissii A. Gray, Man. Ed. 6, 640. 



1890. 

 Aristida Curtissii Nash, in Britt. Man. 94. 1901. 



Culms tufted, 8'-2o' tall, branched; blades ii'-6' 

 long, i"-i" wide, sometimes sparsely pilose above 

 near the base; panicle 2 '-4' long, the branches erect; 

 spikelets commonly 5 "-6" long, rarely longer, the 

 first scale much shorter than the second which usu- 

 ally about equals the body of the flowering scale, 

 rarely somewhat exceeding it, the flowering scale 

 3i"-5i" long, the lateral awns very short, $"-i" 

 long, straight and erect, usually less than \ as long 

 as the central awn which has the straight portion 

 2i"-4" long. 



In dry soil, Missouri and Kansas to Oklahoma ; also 

 in Virginia. Sept.-Oct. 



3. Aristida basiramea Engelm. Forked Triple- 

 awned Grass. Beard-grass. Fig. 425. 



Aristida basiramea Engelm.; Vasey, Coult. Bot. Gaz. 9: 

 76. 1884. 



Glabrous and smooth, culms 6'-i8' tall, erect, slender, 

 much branched. Sheaths shorter than the internodes, 

 loose ; ligule very short, ciliate ; blades 2'-6' long, about 

 i" wide, involute-setaceous; spike-like panicle 3'-$' 

 long; first scale of spikelet half to three-quarters as 

 long as the second, which is 5"-7" in length, both awn- 

 pointed ; third scale shorter than the second ; middle 

 awn 6"-o/' long, coiled at base, horizontal, lateral awns 

 one-quarter to one-half as long, erect or divergent, 

 somewhat spiral at the base. 



In dry fields, Illinois to Minnesota and Nebraska. July- 

 Sept. 



4. Aristida ramosissima Engelm. Branched 

 Aristida. Fig. 426. 



A. ramosissima Engelm.; A. Gray, Man. Ed. 5, 618. 1867. 



Aristida ramosissima var. vniaristata A. Gray, Man. Ed. 

 5, 618. 1867. 



Glabrous, culms 6'-2 tall, erect, slender, branched, 

 smooth. Sheaths much shorter than the internodes, 

 loose; ligule very short; blades ii'~3' long, i" wide or 

 less, flat, attenuate into a long point, smooth beneath, 

 scabrous above; spikelets few, borne in loose spikes 

 from 2'~4' in length ; first scale awn-pointed ; second 

 scale 8"-io" in length, exceeding the first, terminated 

 with an awn i"-3" long; third scale as long as the 

 second ; middle awn about i' long, horizontal or re- 

 flexed and forming a hook, the lateral awns erect, i"-2" 

 long, rarely wanting. 



In dry soil, Indiana to Missouri and Tennessee. July- 

 Sept. 



