Hyparrhenia cyanescens

HABIT Perennial. Rhizomes short. Butt sheaths glabrous. Culms erect, or geniculately ascending; robust; 200–300 cm long; 4–8 mm diam.; without nodal roots, or with prop roots. Leaves cauline. Leaf-sheath auricles absent, or erect; 1–6 mm long. Ligule an eciliate membrane; 2–3 mm long. Leaf-blade base tapering to the midrib. Leaf-blades 15–50 cm long; 3–8 mm wide; glaucous. Leaf-blade surface glabrous.

INFLORESCENCE Synflorescence compound; paniculate; 30–60 cm long. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; exserted, or embraced at base by subtending leaf. Spatheole linear, or lanceolate; 3.5–5 cm long; membranous; glaucous and purple; glabrous. Peduncle 1–5 cm long; pilose above.

Racemes 2; paired; deflexed; 1.7–2.5 cm long; bearing few fertile spikelets; bearing 3–6 fertile spikelets on each. Rhachis fragile at the nodes; ciliate on margins. Rhachis hairs white. Spikelet packing lax. Rhachis internodes linear; 2.5–4 mm long. Rhachis internode tip oblique; flat. Raceme-bases flattened; subequal; 1 mm long; stiffly setose (sparsely); scariously rimmed.

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; 6–8 mm long; larger than 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; 6–8 mm long; longer than fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; glabrous, or puberulous; acute; awned; one glume awned; with 1–2 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 lanceolate; dorsally compressed; 4.5–6 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus oblong to cuneate; 0.5–1.2 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; grey; without keels; keel-less except near apex. Lower glume surface glabrous to pubescent. 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; 28–34 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 tropical, west-central tropical, northeast tropical, and southern tropical.

NOTES Andropogoneae. WDC.

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