No. 17. 

 TRACHYPOGON POLYMORPHUS Hack. 



Rootstock short. Roots strong. 



Culms tufted, smooth, bearded at the joints, unbranched, erect, 2 to 3 feet high. 



Leaves. Lower ones 6 to 12 inches long, about 2 lines wide, attenuated to a 

 point, scabrous, sparingly hairy toward the base; sheaths hairy, the lower ones 

 longer than the internodes, the upper shorter; ligule 1 to 2 lines long, ovate-lance- 

 olate, sparingly hairy. 



Inflorescence a narrow, slender spike, rather loose, 4 to 6 inches long, erect; 

 the rachis slightly hairy at the joints, otherwise smooth. 



Spikelets in pairs. 3 to 4 lines long, each 1 -flowered, the lower flower sessile 

 and male only, the other on a short pedicel and perfect. Male spikelets: first and 

 second glumes thick; first oblong-linear, 7- to 9-nerved, sparsely pubescent, ob- 

 tuse, ciliate at apex; second lanceolate-oblong, 3-nerved, acute; third and fourth 

 thin, hyaline. Female spikelet like the male except the flowering glume; this 

 terminating in a hairy, twisted awn, about 2 inches long. Stamens 3. Styles 2, 

 stigmas plumose. 



Plate XVII; a, pair of spikelets opened to show the parts. 



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