Andropogon tectorum

HABIT Perennial; caespitose. Culms 200–300 cm long; without nodal roots, or with prop roots. Ligule an eciliate membrane, or a ciliolate membrane; 1–2 mm long. Leaf-blade base tapering to the midrib; with a false petiole. Leaf-blades lanceolate; 30–45 cm long; 10–25 mm wide; flaccid; light green. Leaf-blade apex acuminate.

INFLORESCENCE Synflorescence compound; paniculate; lax. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole. Spatheole lanceolate; 4–7 cm long; membranous, or herbaceous.

Racemes 2; paired; 3–4 cm long. Rhachis fragile at the nodes; ciliate on margins. Rhachis hairs 2–3 mm long. Rhachis internodes linear; 3 mm long. Rhachis internode tip transverse; cupuliform; with simple rim.

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

STERILE SPIKELETS Companion sterile spikelets well-developed; male; oblong; dorsally compressed; 4–5 mm long; as long as fertile. Companion sterile spikelet glumes chartaceous; acute; mucronate, or awned; both glumes awned; with 0.5–1.5 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 oblong; dorsally compressed; 4–5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus pilose; base obtuse; inserted. Spikelet callus hairs 1–1.5 mm long.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 1 length of spikelet; membranous; 2-keeled; keeled laterally. Lower glume intercarinal veins distinct. Lower glume surface flat and with a longitudinal median groove. Upper glume lanceolate; membranous; 1-keeled; 3 -veined. Upper glume margins ciliate. Upper glume muticous.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; 3 mm long; hyaline; 2 -veined; ciliate on margins. Fertile lemma linear; 3 mm long; hyaline; without keel. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 15–20 mm long overall; with twisted column. Column of lemma awn glabrous. Palea 0.33 length of lemma.

FLOWER Anthers 3; 2 mm long.

DISTRIBUTION Africa: west tropical, west-central tropical, and northeast tropical.

NOTES Andropogoneae. FTA.

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