MANUAL OF THE GRASSES OF THE UNITED STATES 



211 



Figure 404.— Distribution of 

 Triodia pulchclta. 



3. Triodia pilosa (Buckl.) Merr. Hairy triodia. (Fig. 406.) 



Culms erect, densely tufted, 10 to 30 cm tall, usually only 1 node 



showing, the tufts easily pulled up; sheaths 



pilose at the throat; blades 1 to 1.5 mm wide, 



flat or folded, mostly in a shorty basal cluster, 



somewhat pilose, the margins thick, white, the 



culm blades 1 to 2 cm long; panicle long- 



exserted, ovoid, 1 to 2 cm long, pale or pur- 

 plish, of 3 to 10 large short-pediceled spikelets; 



spikelets 6- to 12-flowered, 1 to 1.5 cm long, 



compressed, glumes about two-thirds as long 



as the lower florets; lemmas about 6 mm long, densely pilose toward 



the base, pilose on the margin toward the tip, 



acute, minutely 2-toothed, the awn 1 to 2 mm 



long; palea half as long as the lemma, pilose 



on the back and margins below. % {Triodia 



acuminata Vasey; Tricus- 

 pis pilosa Nash; Erio- 

 neuron pilosum Nash.) — 

 Plains and rocky hills, 

 western Kansas to Ne- 

 vada, south to Texas, Ar- 

 izona, and central Mexico 

 (fig. 407). 



4. Triodia congesta (L. 

 H. Dewey) Bush. (Fig. 

 408.) Culms erect, tufted, 

 30 to 60 cm tall; blades 

 flat, 2 to 3 mm wide, ta- 

 pering to a fine point; 

 panicle mostly dense, pale 

 or pinkish, 4 to 10 cm long, 

 sometimes interrupted be- 

 low; spikelets rather tur- 

 gid, 6- to 12-flowered, 5 

 to 10 mm long; lemmas 3 

 to 4 mm long, broad, ob- 

 tuse, short-pilose on the 

 midnerve and margin be- 

 low, the apex slightly 

 notched, the awn less than 

 1 mm long; palea about 

 as long as the lemma, 



broad, abruptly bowed out below. % (Tridens congestus Nash.) — 



Sandy or dry plains, southern Texas. 



5. Triodia buckleyana (L. H. Dewey) Vasey. 

 (Fig. 409.) Culms erect, tufted, 30 to 60 cm 

 tall; sheaths, scaberulous, sometimes sparsely 

 pilose; blades flat, 1 to 3 mm wide, tapering 

 to a fine point; panicle 10 to 20 cm long, the 

 few branches distant, ascending to spreading, 

 as much as 7 cm long; spikelets pale to dark 

 purple, short-pediceled, appressed, rather few 



and somewhat distant along the simple branches, 3- to 5-flowered, 6 

 to 8 mm long; glumes slightly shorter than the lower florets; lemmas 



Figure 405.— Triodia grandi- 

 flora. Plant, X Vi, floret, X 

 5. (Eggleston 10973, Ariz.) 



Figure 406.— Triodia pilosa. 

 Plant, X l A; floret, X 5. 

 (Griffiths 6427, Tex.) 



Figure 407.— Distribution of 

 Triodia pilosa. 



