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 didactyla

HABIT Perennial; mat forming. Rhizomes elongated; knotty. Stolons present. Culms prostrate; 15–30 cm long; rooting from lower nodes. Culm-nodes brown; glabrous. Leaf-sheaths smooth, or scaberulous; glabrous on surface. Ligule an eciliate membrane; 0.8 mm long. Leaf-blades 3–6(–10) cm long; 3–6 mm wide; glaucous. Leaf-blade surface smooth; glabrous. Leaf-blade margins scaberulous.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 2–3(–4); paired, or digitate; unilateral; 3–10 cm long. Rhachis wingless, or narrowly winged; with sharp-edged midrib; angular; 0.6 mm wide; smooth on surface; scaberulous on margins.

Spikelets in pairs. Fertile spikelets pedicelled; 2 in the cluster. Pedicels terete, or angular; unequal; 0.5–2.5 mm long; scaberulous; tip widened.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate, or oblong; dorsally compressed; (2–)2.2–2.7 mm long; falling entire.

GLUMES Glumes two; dissimilar; shorter than spikelet; thinner than fertile lemma. Lower glume ovate; 0.1 length of spikelet; membranous; without keels; 0 -veined. Lower glume lateral veins absent. Lower glume apex truncate. Upper glume ovate; 0.33–0.5 length of spikelet; membranous; without keels; 3 -veined. Upper glume surface pubescent. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate; 1 length of spikelet; membranous; 7 -veined; smooth, or scaberulous; rough on veins; pubescent; acute. Fertile lemma lanceolate; 2–2.7 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: southern tropical, south, and western Indian ocean. Asia-tropical: India, Indo-China, Malesia, and Papuasia. Australasia: Australia. Pacific: southwestern. South America: northern South America.

NOTES Paniceae. FZ.

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