Andropogon auriculatus

HABIT Perennial; caespitose. Basal innovations flabellate. Culms 100–150 cm long. Leaf-sheaths keeled. Leaf-sheath auricles erect; 4–10 mm long. Ligule an eciliate membrane; 4–10 mm long. Leaf-blade base tapering to the midrib. Leaf-blades 15–30 cm long; 4–8 mm wide. Leaf-blade surface glabrous, or pubescent; hairy abaxially. Leaf-blade apex attenuate.

INFLORESCENCE Synflorescence compound; paniculate; lax. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole. Spatheole linear; 6–10 cm long.

Racemes 2; paired; 4–7 cm long. Rhachis fragile at the nodes; glabrous on surface, or pubescent on surface; ciliate on margins. Rhachis internodes clavate; 3 mm long. Rhachis internode tip oblique; crateriform; with simple rim.

Spikelets appressed; in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels clavate; 3 mm long; ciliate; tip lobed (bilobed).

STERILE SPIKELETS Companion sterile spikelets well-developed; containing empty lemmas, or male; oblong; dorsally compressed; 4 mm long; shorter than fertile. Companion sterile spikelet glumes chartaceous; acute; awned; one glume awned. Companion sterile spikelet lemmas 2; enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; 5.5–7 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus pilose; base obtuse; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 1 length of spikelet; chartaceous; 2-keeled; keeled laterally. Lower glume intercarinal veins distinct. Lower glume surface flat and with a longitudinal median groove; pubescent; hairy in lines (along midline). Lower glume apex dentate; 2 -fid. Upper glume lanceolate; chartaceous; 1-keeled; 3 -veined. Upper glume surface glabrous, or puberulous. Upper glume margins ciliate. Upper glume muticous.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; 5 mm long; hyaline; 3 -veined; ciliate on margins. Fertile lemma oblong; 4 mm long; hyaline; without keel. Lemma apex lobed; 2 -fid; incised 0.25 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 10–17 mm long overall; with twisted column. Column of lemma awn glabrous. Palea oblong; 0.25 length of lemma; 0 -veined; without keels.

FLOWER Anthers 3; 3 mm long.

DISTRIBUTION Africa: west tropical and west-central tropical.

NOTES Andropogoneae. FTA.

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