Hyparrhenia tuberculata

HABIT Perennial; caespitose. Butt sheaths glabrous. Culms erect; 60 cm long. Leaves cauline. Ligule an eciliate membrane. Leaf-blades 10–15 cm long; 2–3 mm wide; glaucous.

INFLORESCENCE Synflorescence compound; scanty. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; embraced at base by subtending leaf. Spatheole lanceolate; 5–9 cm long; scarious; brown. Peduncle nodding; 1.5–8 cm long; pilose above (yellow hairs).

Racemes 2; paired; erect; 1.5–2 cm long; bearing few fertile spikelets; bearing 3–4 fertile spikelets on each. Rhachis fragile at the nodes; ciliate on margins. Rhachis internodes linear. Rhachis internode tip oblique; flat. Raceme-bases flattened; subequal; 2 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 4 in number; 4 in upper raceme; lanceolate; 7–12 mm long; equalling fertile, or larger than fertile. Basal sterile spikelet glumes tuberculate; pilose; tuberculate on margins and setose on margins (pectinately); lower glume muticous.

Companion sterile spikelets well-developed; containing empty lemmas, or male; lanceolate; dorsally compressed; 7–8 mm long; as long as fertile; separately deciduous. Companion sterile spikelet callus square; 0.2–0.5 mm long; truncate. Companion sterile spikelet glumes chartaceous; smooth, or scabrous; setose on margins; acute; 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; 7–7.5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus cuneate; 1.5–2 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; without keels; keel-less except near apex. Lower glume surface spinose; 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; 40–50 mm long overall; with twisted column. Column of lemma awn hirtellous; with 0.7–1.5 mm long hairs. Palea absent or minute.

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

DISTRIBUTION Africa: northeast tropical.

NOTES Andropogoneae. WDC.

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