GrassBase - The Online World Grass Flora


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

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

Digitaria ctenantha

HABIT Annual. Culms decumbent; 20–60 cm long; 2–5 -noded. Culm-nodes glabrous. Leaf-sheaths without keel; antrorsely scabrous; glabrous on surface, or pilose; outer margin glabrous. Ligule an eciliate membrane; 0.6–2 mm long. Leaf-blades linear, or lanceolate; 3–11 cm long; 2–5 mm wide. Leaf-blade surface scabrous; glabrous, or hirsute. Leaf-blade margins scabrous. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 2–3; paired, or digitate; spreading; unilateral; 2.5–8.5 cm long; bearing 18–30 fertile spikelets on each. Rhachis narrowly winged; angular; 0.9–1 mm wide; scabrous on margins.

Spikelets in pairs. Fertile spikelets pedicelled; 2 in the cluster. Pedicels unequal; 0.4–0.6 mm long; glabrous; tip rectangular.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 3.6–5.3 mm long; 0.9–1.3 mm wide; falling entire.

GLUMES Glumes one the lower absent or obscure, or two; shorter than spikelet; thinner than fertile lemma. Lower glume ovate; 0–0.8 mm long; 0–0.15 length of spikelet; membranous; 0 -veined. Lower glume lateral veins absent. Lower glume apex obtuse, or acute. Upper glume lanceolate; 2.7–3.8 mm long; 0.6–0.8 length of spikelet; membranous; without keels; 3 -veined. Upper glume surface villous. Upper glume margins ciliate. Upper glume apex acuminate.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate; 1 length of spikelet; membranous; 7 -veined; prominently veined; with unevenly spaced veins; pilose and setose; hairy between veins but central interspaces glabrous; acuminate. Fertile lemma lanceolate; 3.6–5.3 mm long; cartilaginous; much thinner on margins; without keel. Lemma surface striate. Lemma margins flat; covering most of palea. Lemma apex acuminate. Palea cartilaginous.

DISTRIBUTION Australasia: Australia.

NOTES Paniceae. Webster 1993.

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