MANUAL OF THE GRASSES OF THE UNITED STATES 



211 









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Figure 404.— Distribution of 

 Triodia pulchella. 



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 short 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 

 acu m inata 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- 

 \o\v\ 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 figure 406.— Triodia pnosa. 

 1 mm long; palea about (Griffiths 6427, t°S * 

 as long as the lemma, 



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

 Sandy or dry plains, southern Texas. 



5. Triodia buckleyana (L. H. Dewev) 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. (Egsleston 10973, Ariz.) 



Figube 407— Distribution of 

 Triodia pilosa. 



