GrassBase - The Online World Grass Flora

Descriptions

W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Hyparrhenia mobukensis

HABIT Perennial. Butt sheaths glabrous. Culms rambling; slender; 100–160 cm long; wiry. Leaves cauline. Ligule an eciliate membrane; 1 mm long. Leaf-blades linear, or lanceolate; tapering towards sheath; 4–8 cm long; 2–5 mm wide; flaccid; light green. Leaf-blade surface glabrous. Leaf-blade apex acuminate.

INFLORESCENCE Synflorescence compound; scanty. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; exserted. Spatheole linear, or lanceolate; 4–5 cm long; membranous. Peduncle flexuous; 5–10 cm long; scaberulous above; glabrous, or pilose above.

Racemes (1–)2; paired; erect; 1.5–3 cm long; bearing few fertile spikelets; bearing 3–7 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 linear, or flattened; unequal (the longer measured); 1.5–3 mm long; pilose, or 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; 2 in number (lower raceme); 0 in upper raceme; lanceolate; 5–6 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 mm long; longer than fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; glabrous; 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; 4–5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus brief (semicircular); 0.5 mm long; pubescent; base obtuse (broadly); 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; 9 -veined. Lower glume surface smooth, or asperulous; glabrous. 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; 7–8 mm long overall; with twisted column. Column of lemma awn glabrous. 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.

NOTES Andropogoneae. WDC.

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