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.

Digitaria incisa

HABIT Annual; culms solitary, or caespitose. Culms erect, or geniculately ascending; 70–100 cm long. Culm-internodes terete; distally glabrous. Culm-nodes glabrous. Leaf-sheaths mostly shorter than adjacent culm internode; smooth; glabrous on surface. Ligule a ciliolate membrane; 0.5 mm long; truncate. Leaf-blades 7–15 cm long; 3–5 mm wide. Leaf-blade midrib prominent beneath. Leaf-blade surface smooth; glabrous. Leaf-blade margins cartilaginous; scaberulous.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 2–4; paired, or digitate; unilateral; 10–15 cm long. Rhachis angular; glabrous on surface; scaberulous on margins.

Spikelets in pairs. Fertile spikelets pedicelled; 2 in the cluster. Pedicels angular; unequal; 0.2–2.5 mm long; scabrous; tip widened.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate, or oblong; dorsally compressed; 2.7–3.1 mm long; falling entire.

GLUMES Glumes two; dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume oblate; clasping; 0.5–1 mm long; 0.2–0.33 length of spikelet; hyaline; pallid; without keels; 0 -veined. Lower glume lateral veins absent. Lower glume apex dentate; 2 -fid. Upper glume lanceolate, or oblong; 2.7–3.1 mm long; 1 length of spikelet; membranous; without keels; 5 -veined. Upper glume surface pubescent; hairy between veins; with verruculose hairs. Upper glume margins pubescent. Upper glume apex obtuse.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; 1 length of spikelet; membranous; 7 -veined; pubescent; hairy between veins; with hooked hairs; with basal tufts of hair; 2 hair tufts in all; pubescent on margins; bearing hairs 0.7–0.8 mm long; acute. Fertile lemma lanceolate to oblong; 2.5–3 mm long; cartilaginous; much thinner on margins; yellow, or light brown; without keel. Lemma margins flat; covering most of palea. Lemma apex acute. Palea cartilaginous.

DISTRIBUTION Africa: west-central tropical.

NOTES Paniceae. Van der Veken 2001.

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