Schizachyrium nodulosum

HABIT Annual. Culms erect; 15–45 cm long. Ligule an eciliate membrane. Leaf-blades 3–8 cm long; 2–3 mm wide. Leaf-blade apex acuminate.

INFLORESCENCE Synflorescence compound; scanty. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; embraced at base by subtending leaf. Spatheole lanceolate; 2.5–3 cm long; red.

Racemes 1; single; smoothly terete; 2.5–5 cm long. Rhachis fragile at the nodes; subterete; 2 mm wide; pubescent on surface; pubescent on margins. Rhachis internodes oblong; 4–5 mm long. Rhachis internode tip crateriform; with scarious rim.

Spikelets squeezed between internode and pedicel; in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels linear; pubescent.

STERILE SPIKELETS Companion sterile spikelets well-developed; comprising 2 subequal glumes without lemmas; lanceolate; dorsally compressed; 3 mm long; shorter than fertile; deciduous with the fertile. Companion sterile spikelet glumes membranous; awned; one glume awned; with 1–2 mm long awn.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets linear; dorsally compressed; 5–7 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus bearded; base obtuse; inserted. Spikelet callus hairs 1.5 mm long.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume linear; 1 length of spikelet; chartaceous; 2-keeled; keeled frontally. Lower glume intercarinal veins obscure; 3 in number. Lower glume surface glabrous. Lower glume apex dentate; 2 -fid. Upper glume lanceolate; membranous; 1-keeled; 1–3 -veined. Upper glume primary vein ciliate. Upper glume margins ciliate. Upper glume mucronate.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; 2 mm long; hyaline; 0 -veined. Fertile lemma ovate; hyaline; without keel. Lemma apex lobed; 2 -fid; incised 0.6–0.75 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 10–12 mm long overall; with twisted column. Column of lemma awn glabrous. Palea absent or minute.

FLOWER Anthers 3; 1 mm long.

FRUIT Caryopsis with adherent pericarp; lanceolate; 3 mm long. Embryo 0.5 length of caryopsis.

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.