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 subplumosa

HABIT Perennial; caespitose. Butt sheaths glabrous. Culms erect; robust; 200–300 cm long. Leaves cauline. Leaf-sheaths glabrous on surface, or pilose. Leaf-sheath oral hairs bearded (grey hairs). Ligule an eciliate membrane; 2–3 mm long. Leaf-blades 20–60 cm long; 3–10 mm wide; glaucous. Leaf-blade surface glabrous, or hirsute; sparsely hairy; hairy abaxially. Leaf-blade margins scabrous.

INFLORESCENCE Synflorescence compound; paniculate; 20–50 cm long. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; enclosed. Spatheole lanceolate; 3–7 cm long; membranous; glaucous, or purple. Peduncle straight, or nodding; 1–3.5 cm long; glabrous, or hirsute above.

Racemes 2; paired; deflexed; 1.5–2.5 cm long; bearing few fertile spikelets; bearing 1–3 fertile spikelets on each. Rhachis fragile at the nodes; ciliate on margins. Rhachis internodes linear. Rhachis internode tip oblique; flat. Raceme-bases flattened; subequal; 1.5–2 mm long; pubescent.

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; forming an involucre about the fertile; lanceolate; 8–10 mm long; larger than fertile. Basal sterile spikelet glumes glabrous, or pubescent; scabrous on margins; 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 glumes chartaceous; acute; awned; one glume awned; with 2–7 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; 6.5–7.5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus cuneate; 1.5 mm long; pubescent; base acute; 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 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; 45–75 mm long overall; with twisted column. Column of lemma awn hirsute; with 0.5–1.3(–1.7) mm long hairs. Palea absent or minute.

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

FRUIT Caryopsis 3.5 mm long.

DISTRIBUTION Africa: west tropical, 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.