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 orbata

HABIT Perennial; caespitose. Rhizomes elongated. Culms erect; 40–85 cm long; 3–5 -noded. Leaf-sheaths glabrous on surface. Ligule an eciliate membrane; 1.6–4 mm long. Leaf-blades 6–25 cm long; 1.8–5.5 mm wide. Leaf-blade surface scabrous; glabrous.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 2–10; borne along a central axis; unilateral; 7–16 cm long; bearing 30–70 fertile spikelets on each. Rhachis angular.

Spikelets in pairs. Fertile spikelets pedicelled; 2 in the cluster. Pedicels 0.4–0.8 mm long; tip cupuliform.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; acute; 1.3–1.8 mm long; 0.46–0.8 mm wide; falling entire.

GLUMES Glumes one the lower absent or obscure; shorter than spikelet; thinner than fertile lemma. Upper glume elliptic, or ovate; 0.2–0.6 mm long; 0.33 length of spikelet; hyaline; without keels; 0 -veined. Upper glume primary vein absent. Upper glume lateral veins absent. Upper glume surface glabrous. Upper glume margins eciliate. Upper glume apex emarginate, or truncate, or obtuse.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret elliptic; 1.1–1.6 mm long; 0.9 length of spikelet; membranous; 3–5 -veined; with equidistant veins, or with unevenly spaced veins; puberulous; hairy between veins but central interspaces glabrous; eciliate on margins; obtuse. Fertile lemma elliptic; 1.2–1.7 mm long; cartilaginous; much thinner on margins; dark brown; without keel. Lemma margins flat; covering most of palea. Lemma apex obtuse, or acute, or apiculate. Palea cartilaginous.

DISTRIBUTION Australasia: Australia.

NOTES Paniceae. Fl Austral. ms 2015.

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