Andropogon imerinensis

HABIT Perennial; caespitose. Culms erect; slender; 20–60 cm long; 2–3 -noded. Culm-nodes glabrous. Lateral branches lacking. Leaves mostly basal. Leaf-sheaths keeled; glabrous on surface, or pilose. Leaf-sheath oral hairs scanty, or lacking. Ligule a ciliolate membrane; 0.5 mm long; membranous; truncate. Leaf-blades erect; straight; filiform; flat, or convolute; 6–25 cm long; 0.3–1 mm wide; stiff; red. Leaf-blade surface glabrous; hairless throughout, or except near base. Leaf-blade margins smooth, or scaberulous. Leaf-blade apex attenuate; filiform.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 2–3; paired, or digitate; 1.5–4.5 cm long. Rhachis fragile at the nodes; ciliate on margins. Rhachis hairs 1.5–3 mm long. Rhachis internodes filiform; 2–4.5 mm long. Rhachis internode tip transverse; cupuliform; with simple rim.

Spikelets ascending; in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels filiform; ciliate; with 1.5–3 mm long hairs.

STERILE SPIKELETS Companion sterile spikelets well-developed; male; lanceolate; 3.5–5.5 mm long; as long as fertile. Companion sterile spikelet glumes chartaceous; glabrous; acute; muticous, or mucronate. Companion sterile spikelet lemmas enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate, or oblong; dorsally compressed; 3.5–5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus brief; pilose; base obtuse; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 3.5–5 mm long; 1 length of spikelet; chartaceous; 2-keeled; keeled laterally; 4–6 -veined. Lower glume intercarinal veins absent. Lower glume surface concave. Upper glume lanceolate; membranous; 1-keeled; 3–5 -veined. Upper glume muticous.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; 4–4.5 mm long; hyaline; 0–3 -veined; without midvein, or with evident midvein; without lateral veins, or distinctly veined; ciliate on margins; fringed above. Fertile lemma lanceolate; 4 mm long; hyaline; without keel; 1–3 -veined. Lemma margins ciliolate. Lemma apex lobed; 2 -fid; incised 0.66 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 10–13 mm long overall; with twisted column. Column of lemma awn glabrous. Palea 1 mm long.

FLOWER Anthers 3.

DISTRIBUTION Africa: western Indian ocean.

NOTES Andropogoneae. Vorontsova 2013.

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