Hyparrhenia formosa

HABIT Perennial; caespitose. Butt sheaths glabrous. Culms erect; robust; 150–200 cm long; without nodal roots, or with prop roots. Leaves cauline. Ligule an eciliate membrane; 2 mm long. Leaf-blades 25–50 cm long; 6–12 mm wide. Leaf-blade surface scaberulous.

INFLORESCENCE Synflorescence compound; paniculate; 30–40 cm long; dense. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; enclosed. Spatheole lanceolate; 1.8–2.6 cm long; membranous; red; glabrous, or pilose (rarely). Peduncle 0.2–1 cm long; pilose above.

Racemes 2; paired; deflexed; 1–1.5 cm long; bearing few fertile spikelets; bearing 3–4 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 flattened; subequal; 0.2–0.5 mm long; stiffly setose.

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; 4.5–5.5 mm long; equalling fertile. Basal sterile spikelet glumes glabrous; ciliate on margins; lower glume muticous.

Companion sterile spikelets well-developed; containing empty lemmas, or male; lanceolate; dorsally compressed; 4.5–6 mm long; as long as fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; glabrous, or pubescent; acuminate; muticous. 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; 4–4.5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus oblong to cuneate, or square (rarely); 0.5–1 mm long; pubescent; base obtuse; attached obliquely.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of spikelet; coriaceous; without keels; keel-less except near apex. Lower glume surface glabrous, or pilose. 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; 8–18 mm long overall; with twisted column. Column of lemma awn puberulous, or pubescent; with 0.2–0.4 mm long hairs. Palea absent or minute.

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

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

NOTES Andropogoneae. WDC.

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