Chasmanthium sessiliflorum

Culms 60-150 cm, (1)2-3.5 mm thick at the nodes, unbranched, leafy for 40% of their height. Sheaths pilose; collars pilose; ligules 0.2-0.3 mm, entire; blades (15)20-50 cm long, 4.5-9.5(15) mm wide, linear-lanceolate, sparsely pilose adaxially. Panicles (9)20-70 cm, contracted or open, erect; branches tightly appressed or ascending to strongly divergent; axils of panicle branchesglabrous or scabridulous at the edges; pedicels 0.3-2.5(5) mm. Spikelets 4-10 mm long, 6-9 mm wide, with 4-7(8) florets, lower 1(2) florets sterile, fertile florets divergent to 80°. Lower glumes 1.2-2.7 mm, 3-5-veined; upper glumes 1.4-2.2 mm, 3-5-veined; calluses glabrous; fertile lemmas 3.5-5.9 mm, usually curved or irregularly contorted, 7-9-veined, keels not winged, apices scabridulous; paleas 2.8-4 mm; anthers (0.8)1.3-1.6 mm, varying in length within a spikelet. Caryopses 2-2.5 mm, exposed at maturity. 2n =24.

Chasmanthium sessiliflorum grows in rich woods, meadows, and swamps, especially on the coastal plain. It grows throughout most of the southeastern United States.

Much like no. 2 [Chasmanthium laxum (L.) H. O. Yates], but the sheaths villous at the summit or throughout; lvs mostly 6-12 mm wide; 2n=24. Moist open woods and streambanks; Fla. to Tex., n. to se. Va., Tenn., and e.c. Mo. (Uniola s.)

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

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