38. Chloris Sw. (windmill grass)
(Anderson, 1974)
Plants annual or perennial, without rhizomes (with rhizomes
or stolons elsewhere), forming tufts or clumps. Flowering stems erect to
prostrate or spreading, often rooting at the lower nodes, somewhat to strongly
flattened, glabrous. Leaf sheaths slightly to strongly keeled on the back,
glabrous or hairy near the tip, the ligule absent or more commonly a short
membrane with hairs along the margin. Leaf blades keeled or somewhat folded
near the base, otherwise flat, glabrous or roughened. Inflorescences with 4–20
spikes, these arranged palmately at the tip of the axis or in 2–5 whorls along
the axis. Spikes with numerous spikelets, these ascending or appressed in 2
rows along 1 side of the slender, trigonous axis, disarticulating above the
glumes (leaving the axis of the spike appearing chaffy or scaly after the
florets have been shed). Spikelets with 1 perfect floret below usually 1
reduced, sterile floret. Glumes unequal in size and shape, the lower glume
narrower and shorter than the upper glume, both narrowly lanceolate, 1‑nerved
or rarely 3‑nerved and sharply pointed to short‑awned at the tip.
Lemmas of fertile florets 3‑nerved, the tip narrowed abruptly to an awn,
this sometimes attached between 2 minute teeth. Lemmas of sterile florets
smaller than those of the fertile florets, more or less wedge‑shaped and
truncate at the tip, awned. Paleas of fertile florets 2‑keeled (absent in
sterile florets). Anthers 0.3–0.7 mm long, reddish purple. Fruits 1.3–2.0 mm
long, narrowly elliptic to ovate in outline, circular to trigonous in cross‑section,
brown to reddish brown. About 55 species, nearly worldwide, mostly in tropical
regions.