35. Chasmanthium Link
(Yates, 1966a, b)
Plants with C3 photosynthesis, perennial. Aerial
stems annual, not woody, unbranched or less commonly few‑branched from
near the base. Leaf sheaths open most of their length, the ligule membranous,
hairy along the edge (reduced to a fringe of hairs elsewhere). Leaf blades
flat, usually with a noticeable midvein. Inflorescences panicles, with mostly
numerous spikelets. Spikelets flattened laterally, with 3–20 florets, the axis
extended past the uppermost fertile floret and with a terminal, reduced,
sterile floret, the lowermost 1–3 florets also sterile, the remaining 2–20
florets perfect, disarticulating above the glumes and between the florets.
Glumes 2, about equal in size and shape, shorter than the florets, awnless, keeled,
3–7‑nerved, glabrous or the midnerve roughened. Lemmas awnless, keeled,
5–15‑nerved, glabrous except for the roughened to hairy midnerve. Paleas
shorter than the lemmas, strongly 2‑nerved, the nerves usually narrowly
and unevenly winged. Stamen 1. Fruits ovate to elliptic in outline, flattened,
brown to reddish black or black. Four species, eastern U.S. west to Nebraska
and Texas; Mexico.
Yates (1966a, b) presented a variety of data to show that
the genus Uniola L., as traditionally circumscribed, contains unrelated
species groups that are now placed in different genera in different tribes.
True Uniola presently is classified in the tribe Eragrostideae and
consists of 2–4 species not found in Missouri that occur mostly in coastal sand
dunes.
The species of Chasmanthium all have self‑compatible
florets, and C. latifolium sometimes produces spikelets with
cleistogamous florets (Tucker, 1990).