Hyparrhenia welwitschii

HABIT Annual. Butt sheaths glabrous. Culms erect; 20–300 cm long; without nodal roots, or with prop roots. Culm-nodes glabrous, or bearded. Leaves cauline. Ligule an eciliate membrane; 3 mm long. Leaf-blades tapering towards sheath; 30–60 cm long; 6–12 mm wide; glaucous.

INFLORESCENCE Synflorescence compound; paniculate; 30–60 cm long. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; embraced at base by subtending leaf. Spatheole lanceolate; 3–5 cm long; membranous; glabrous. Peduncle 2.5–4 cm long; pilose above.

Racemes 2; paired; deflexed; 1.2–1.7 cm long; bearing few fertile spikelets; bearing 1 fertile spikelets on each, or 2 fertile spikelets on each (3-awned per pair). Rhachis fragile at the nodes; ciliate on margins. Rhachis internodes linear. Rhachis internode tip oblique; flat. Raceme-bases flattened; subequal; 1–1.5 mm long; stiffly setose; extended into an oblong appendage; with 0.5–1 mm long appendage.

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; on lower raceme 2 in number; 0 in upper raceme; lanceolate; 7–10 mm long; larger than fertile. Basal sterile spikelet glumes glabrous; smooth on margins; lower glume muticous.

Companion sterile spikelets well-developed; containing empty lemmas, or male; lanceolate; dorsally compressed; 6–8 mm long; as long as fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; glabrous; acute; awned; one glume awned; with 2–11(–14) 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, or oblong; dorsally compressed; 5–7 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus cuneate; 1.5 mm long; pubescent; base pungent; attached obliquely.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of spikelet; coriaceous; grey; without keels; keel-less except near apex. Lower glume surface glabrous, or pubescent. Lower glume hairs white. 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; 40–70 mm long overall; with twisted column. Column of lemma awn pubescent. Palea absent or minute.

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

FRUIT Caryopsis 3 mm long.

DISTRIBUTION Africa: west tropical, west-central tropical, northeast tropical, east tropical, southern tropical, and western Indian ocean.

NOTES Andropogoneae. WDC.

ADDITIONAL CHARACTERS Peduncle hairs white or yellow.

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