49. Leptochloa P. Beauv. (feather grass, sprangletop)
Plants annual or perennial, forming tufts or clumps.
Flowering stems spreading to erect, sometimes ascending from spreading bases,
sometimes rooting at the lower nodes, circular in cross‑section or
slightly flattened, often darkened at the nodes, glabrous. Leaf sheaths rounded
on the back or keeled, glabrous or sparsely hairy, the ligule a membrane, often
with hairy or irregularly divided margins. Leaf blades flat or the margins
becoming inrolled when dry, glabrous or roughened on one or both surfaces.
Inflorescences consisting of 7 to usually numerous spikelike racemes, these
mostly alternate along the main axis, ascending to less commonly spreading, the
whole inflorescence much longer than wide. Spikelike racemes with numerous,
densely to loosely spaced, short‑stalked spikelets positioned in 2 rows
on 1 side of the slender axis, this usually not prolonged past the terminal
spikelet. Spikelets flattened laterally, with 2–12 florets, disarticulating
above the glumes. Glumes slightly unequal in size, varying from shorter than
the adjacent lemmas to longer than the rest of the spikelet, 1(3)‑nerved,
keeled, awnless or short‑awned, roughened along the midnerve. Lemmas
lanceolate to ovate, bluntly to sharply pointed at the tip, sometimes with a
minute notch or 2 short teeth, 3‑nerved, awnless or short‑awned,
hairy along the nerves, at least toward the base, sometimes nearly glabrous.
Paleas slightly shorter than the lemmas, 2‑nerved, often somewhat folded
longitudinally. Stamens (2)3. Fruits brown. Thirty‑two to 40 species, nearly
worldwide, mostly in tropical and warm‑temperate regions.
The classification of Leptochloa used here follows
that of Snow (1997, 1998), who recently completed a comprehensive revision of
the genus as part of his doctoral dissertation. Snow has presented evidence for
keeping the segregate genus Diplachne as part of Leptochloa and
also argued convincingly for broadened species concepts in some portions of the