Andropogon gabonensis

HABIT Perennial; caespitose. Culms robust; 200–300 cm long. Ligule a ciliolate membrane; 2–3 mm long. Collar without external ligule. Leaf-blade base tapering to the midrib. Leaf-blades 30–60 cm long; 10–25 mm wide. Leaf-blade margins scabrous. Leaf-blade apex attenuate.

INFLORESCENCE Synflorescence compound; paniculate; 60–90 cm long; lax. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole. Spatheole lanceolate, or elliptic; 5–7 cm long; scarious, or herbaceous.

Racemes 2; paired; 3.5–5 cm long. Rhachis fragile at the nodes; glabrous on surface, or pubescent on surface; pubescent on margins (sparsely). Rhachis internodes oblong. 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 clavate; pubescent (sparsely); tip lobed (bilobed).

STERILE SPIKELETS Companion sterile spikelets well-developed; male; lanceolate; dorsally compressed; 4–4.5 mm long; as long as fertile. Companion sterile spikelet glumes chartaceous; 7–11 -veined; glabrous, or pubescent; acute; muticous, or mucronate. Companion sterile spikelet lemmas 2; enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 4–5 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 lanceolate; 1 length of spikelet; chartaceous; 2-keeled; keeled laterally. Lower glume intercarinal veins distinct. Lower glume surface flat and with a longitudinal median groove; glabrous, or pubescent; hairy in lines (along midline). Upper glume lanceolate; chartaceous; 1-keeled; 3 -veined. Upper glume muticous.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; hyaline; 2 -veined; ciliate on margins. Fertile lemma oblong; hyaline; without keel; 1–3 -veined. Lemma apex lobed; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 9–12 mm long overall; with twisted column. Column of lemma awn glabrous. Palea oblong.

FLOWER Anthers 3; 3 mm long.

DISTRIBUTION Africa: west-central tropical and southern tropical.

NOTES Andropogoneae. FTA.

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