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 trinervis

HABIT Perennial; mat forming. Culms prostrate; 10–20 cm long. Culm-nodes brown; pubescent. Leaf-sheaths smooth, or scaberulous; glabrous on surface, or pilose. Ligule an eciliate membrane; 2 mm long; erose; truncate. Leaf-blades 3–5 cm long; 1–3 mm wide. Leaf-blade surface scaberulous; rough abaxially. Leaf-blade margins scaberulous.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 3–8; borne along a central axis; unilateral; 1–4 cm long. Rhachis wingless; angular; 0.2 mm wide; scaberulous on margins.

Spikelets in pairs. Fertile spikelets pedicelled; 2 in the cluster. Pedicels angular; unequal; 0.5–3 mm long; scaberulous; tip widened.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 2.1–2.4 mm long; falling entire.

GLUMES Glumes two; dissimilar; shorter than spikelet; thinner than fertile lemma. Lower glume ovate; 0.1–0.2 length of spikelet; hyaline; mid-green, or purple; without keels; 0 -veined. Lower glume lateral veins absent. Lower glume apex truncate, or obtuse. Upper glume oblong; 0.75 length of spikelet; membranous; mid-green, or purple; without keels; 3(–5) -veined. Upper glume surface glabrous. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; 1 length of spikelet; membranous; 7 -veined; with unevenly spaced veins; glabrous; acute. Fertile lemma elliptic; 2.1–2.4 mm long; cartilaginous; much thinner on margins; purple; without keel. Lemma margins flat; covering most of palea. Lemma apex acute, or acuminate. Palea cartilaginous.

DISTRIBUTION Africa: southern tropical.

NOTES Paniceae. FZ.

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