Hyparrhenia dichroa

HABIT Perennial; caespitose. Butt sheaths glabrous. Culms erect; robust; 150–300 cm long. Leaves cauline. Ligule an eciliate membrane; 1 mm long. Leaf-blades 30–60 cm long; 4–8 mm wide; stiff.

INFLORESCENCE Synflorescence compound; paniculate; 20–60 cm long. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; embraced at base by subtending leaf. Spatheole lanceolate; 2–3.5 cm long; membranous. Peduncle 1–2.5 cm long; glabrous, or pilose above.

Racemes 2; paired; erect; 1–1.5(–2) cm long; bearing few fertile spikelets; bearing 3–5 fertile spikelets on each. Rhachis fragile at the nodes; ciliate on margins. Rhachis hairs white. Rhachis internodes linear. Rhachis internode tip oblique; flat. Raceme-bases filiform; unequal (the longer measured); 1.5–2.5 mm long; glabrous, or pilose.

Spikelets appressed; in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels linear; flattened; ciliate; tip oblique.

STERILE SPIKELETS Basal sterile spikelets well-developed; 2 in number (lower raceme); 0 in upper raceme, or 2 in upper raceme; lanceolate; equalling fertile. Basal sterile spikelet glumes smooth on margins; lower glume muticous.

Companion sterile spikelets well-developed; containing empty lemmas, or male; lanceolate; dorsally compressed; 3–5 mm long; as long as fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; 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 cuneate; 0.4–0.8 mm long; pubescent; base obtuse; attached obliquely.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma; shiny. Lower glume lanceolate; 1 length of spikelet; coriaceous; dark brown; without keels; keel-less except near apex. Lower glume surface pubescent. Lower glume hairs red. Lower glume apex dentate; 2 -fid. Upper glume linear; coriaceous; without keels.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate; 1 length of fertile lemma; hyaline; 2 -veined. Fertile lemma linear; membranous; without keel; 1 -veined. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 20–30 mm long overall; with twisted column. Column of lemma awn pubescent (rufously). Palea absent or minute.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3. Stigmas 2.

DISTRIBUTION Africa: west-central tropical, northeast tropical, east tropical, southern tropical, and south.

NOTES Andropogoneae. WDC.

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