Andropogon distachyos

HABIT Perennial; caespitose. Butt sheaths pubescent. Culms 25–100 cm long. Ligule an eciliate membrane. Leaf-blades 7–20 cm long; 1–5 mm wide.

INFLORESCENCE Inflorescence composed of racemes; terminal.

Racemes 2; paired; 4–14 cm long. Rhachis fragile at the nodes; ciliate on margins. Rhachis internodes linear, or clavate (slightly). Rhachis internode tip transverse; crateriform; with simple rim.

Spikelets appressed; in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels linear, or clavate (slightly); ciliate.

STERILE SPIKELETS Companion sterile spikelets well-developed; male; lanceolate; dorsally compressed; 6–11 mm long; shorter than fertile; persistent. Companion sterile spikelet glumes herbaceous; dentate; 2 -fid; acuminate; awned; one glume awned; with 3–9 mm long awn. Companion sterile spikelet lemmas enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 8–16 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus oblong; 1–2 mm long; pilose; base obtuse; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; asymmetrical; 1 length of spikelet; herbaceous, or coriaceous; much thinner above; 2-keeled; keeled laterally; winged on keel; winged broadly; winged above (0.5–0.66 length). Lower glume intercarinal veins distinct; 7–11 in number. Lower glume surface convex, or flat, or concave; glabrous, or pubescent. Lower glume apex dentate; 2 -fid; caudate. Upper glume lanceolate; chartaceous; 1-keeled; keeled above. Upper glume awned; 1 -awned. Upper glume awn 4–10 mm long.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; hyaline; 2 -veined. Fertile lemma oblong; hyaline; without keel. Lemma apex lobed; 2 -fid; incised 0.5 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 15–30 mm long overall; with twisted column. Column of lemma awn glabrous. Palea hyaline; 0 -veined; without keels.

DISTRIBUTION Europe: southwestern and southeastern. Africa: north, Macaronesia, west-central tropical, northeast tropical, east tropical, southern tropical, and south. Asia-temperate: western Asia and Arabia. Asia-tropical: Indo-China. Australasia: Australia.

NOTES Andropogoneae. FTEA.

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.