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MISC. PUBLICATION 200, U. S. DEPT. OF AGRICULTURE 



Figure 280. — Tridens buckleyanus. Panicle, X 1; 

 floret, X 5. (Tharp 2996, Tex.) 



5-flowered, 6 to 8 mm. long; glumes 

 slightly shorter than the lower florets; 

 lemmas 4 to 5 mm. long, pubescent on 

 the callus and on the lower two-thirds 

 of the midnerve and margin, the apex 

 obtuse, entire, the midnerve not or 





Figure 281. — Trident carolinianus. Plant, X 1; floret, 

 X 5. (Bartlett 3224, Ala.) 



scarcely excurrent; palea a little 

 shorter than the lemma, pubescent 

 along the margins; grain elliptic, 3 

 mm. long. % — Rocky wooded 

 slopes, southern Texas. 



7. Tridens carolinianus (Steud.) 

 Henr. (Fig. 281.) Culms slender, 

 erect, 1 to 1.5, m. tall, with creeping 

 scaly rhizomes; lower sheaths pubes- 

 cent; blades flat, elongate, 2 to 7 mm. 

 wide; panicle purplish, narrow, rather 

 loose, nodding, 10 to 20 cm. long, the 

 branches appressed or narrowly as- 

 cending ; spikelets short-pediceled, 3- 

 to 5-flowered, 7 to 10 mm. long; 

 glumes broad, mucronate from a 

 notched apex; lemmas about 5 mm. 

 long, pilose on the callus and on the 

 lower half of the midnerve and mar- 

 gins, the summit lobed, the 3 nerves 

 excurrent less than 1 mm. ; palea gla- 

 brous, a little shorter than the lemma, 

 bowed out below. % (Triodia 

 drummondii Scribn. and Kearn., 

 Tridens drummondii Nash.) — Sandy 

 woods, Coastal Plain, South Carolina 

 to Florida and Louisiana. 



8. Tridens ambiguus (Ell.) Schult. 

 (Fig. 282.) Culms slender, erect, 60 to 

 100 cm. tall; lower sheaths glabrous; 

 blades flat or loosely involute, 1 to 5 

 mm. wide; panicle open, ovoid, pale 

 or purplish, 8 to 20 cm. long, the 

 branches ascending, 3 to 8 cm. long; 

 spikelets on pedicels less than 1 mm. 

 long along the simple branches, 4- to 

 7-flowered, 4 to 6 mm. long, nearly as 

 broad, the florets crowded; glumes 

 broad, subacute; lemmas 3 to 4 mm. 

 long, mucronate from a minutely 

 lobed apex, the lateral nerves scarcely 

 or barely exserted, pilose on the mid- 

 nerve and margins on the lower half; 

 palea nearly as long as the lemma, the 

 keels bowed out below. % {Triodia 

 langloisii (Nash) Bush.) — "Wet pine 

 barrens, on the coast, South Carolina 

 to Florida and Texas. 



9. Tridens eragrostoides (Vasey 

 and Scribn.) Nash. (Fig. 283.) Culms 

 slender, erect, densely tufted, 50 to 

 100 cm. tall; blades flat, 1 to 4 mm. 

 wide, setaceous-tipped; panicle open, 

 10 to 30 cm. long, the branches rather 



