Schizachyrium ruderale

HABIT Annual. Culms 150–200 cm long; 3–4 mm diam. Ligule a ciliolate membrane; 2 mm long. Leaf-blades 10–25 cm long; 3–6 mm wide. Leaf-blade surface glabrous, or pilose; sparsely hairy. Leaf-blade apex abruptly acute.

INFLORESCENCE Synflorescence compound; paniculate; 30–60 cm long. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole. Spatheole linear; 3 cm long; brown, or purple. Peduncle 1 cm long.

Racemes 1; single; 5–7 cm long. Rhachis fragile at the nodes; 0.75 mm wide; ciliate on margins. Rhachis internodes cuneate; 6.5 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 cuneate; 4 mm long; ciliate; tip lobed.

STERILE SPIKELETS Companion sterile spikelets well-developed; male; lanceolate; dorsally compressed; 4.5 mm long; shorter than fertile; deciduous with the fertile. Companion sterile spikelet glumes chartaceous; 11 -veined; scaberulous; ciliate on margins; dentate; 2 -fid; awned; one glume awned; with 3–10 mm long awn. Companion sterile spikelet lemmas 2; enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets linear; dorsally compressed; 7–8 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus oblong; 0.75 mm long; bearded; base obtuse; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume linear; 1 length of spikelet; coriaceous; 2-keeled; keeled frontally. Lower glume intercarinal veins distinct. Lower glume surface asperulous; villous; hairy below. Lower glume margins ciliate. Lower glume apex dentate; 2 -fid. Upper glume lanceolate; membranous; 1-keeled. Upper glume margins ciliolate.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret linear; 4 mm long; hyaline. Fertile lemma oblong; 2 mm long; hyaline; without keel. Lemma margins ciliolate. Lemma apex lobed; 2 -fid; incised 0.9 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 14–20 mm long overall; with twisted column. Column of lemma awn 7 mm long; glabrous. Palea absent or minute.

FLOWER Lodicules 2; cuneate; 0.2 mm long. Anthers 3; 2.5 mm long.

DISTRIBUTION Africa: west tropical.

NOTES Andropogoneae. WDC.

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