Hyparrhenia niariensis

HABIT Annual. Butt sheaths glabrous. Culms erect; 100–200 cm long; with prop roots. Leaves cauline. Ligule an eciliate membrane. Leaf-blade base tapering to the midrib; without a false petiole, or with a false petiole. Leaf-blades 30–60 cm long; 7–15 mm wide. Leaf-blade surface glabrous, or pubescent; hairy abaxially.

INFLORESCENCE Synflorescence compound; paniculate; 30–50 cm long. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; exserted. Spatheole lanceolate; 3–5 cm long; membranous; glabrous, or pilose. Peduncle 3–5 cm long; pilose above.

Racemes 2; paired; deflexed; 1.5–1.8 cm long; bearing few fertile spikelets; bearing 1(–2) fertile spikelets on each. Rhachis fragile at the nodes; ciliate on margins. Rhachis internodes linear. Rhachis internode tip oblique; flat. Raceme-bases flattened; subequal; 0.5–1.5 mm long; stiffly setose (yellow hairs); scariously rimmed (rarely), or extended into an oblong appendage; with (0.2–)0.5–4 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; 9–11 mm long; equalling 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; 8–13 mm long; longer than fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; acute; awned; one glume awned; with 2–10 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 oblong; dorsally compressed; 7.5–11 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus cuneate; 2–3 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; chartaceous, or coriaceous; without keels; keel-less except near apex. Lower glume surface convex, or concave; glabrous. Lower glume apex dentate; 2 -fid. Upper glume linear; chartaceous, or 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; 65–85(–105) 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 4 mm long.

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

NOTES Andropogoneae. WDC.

ADDITIONAL CHARACTERS Peduncle hairs yellow.

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