Tridens flavus (L.) Hitchc.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Tufted and sometimes with very short rhizomes, 8–15 dm; sheaths bearded at the top, otherwise glabrous, as are the blades, these 3–8 mm wide, elongate to a slender tip; infl viscid, with loosely spreading-ascending branches villous at base above; spikelets purple (yellow), narrowly ovoid, scarcely compressed, 5–10 mm, 4–9-fld, the lateral ones appressed along the branchlets or on looser pedicels to ca 3 mm; glumes unequal, firm, oblong or ovate, 2.5–3.5 mm, 1- veined, obtuse or often mucronate; lemmas regularly imbricate, densely villous on the basal half; 2n=40. Fields, roadsides, and open woods; Mass. to s. Ont., s. Mich., and Nebr., s. to Fla. and Tex. (Triodia f.) Most of our plants belong to the widespread var. flavus, as principally described above. The more strictly southeastern var. chapmanii (Small) Shinners reaches our range in se. Va. and s. N.J. It has more divergent panicle-branches, villous all around at the more strongly buttressed base, and the spikelets are on longer, more divergent pedicels mostly 3–20 mm. (T. c.)