Digitaria gibbosa

HABIT Annual. Culms erect; 25–40 cm long; 2–5 -noded. Culm-nodes glabrous. Leaf-sheaths without keel; antrorsely scabrous; glabrous on surface, or pubescent; outer margin glabrous. Leaf-sheath auricles erect. Ligule a ciliolate membrane; 0.3–1 mm long. Leaf-blades linear, or lanceolate; 2.5–15 cm long; 1–4 mm wide. Leaf-blade surface scabrous.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; unilateral; 4–18 cm long; simple, or secondarily branched. Rhachis wingless; angular; 0.35–0.45 mm wide; smooth on margins, or scaberulous on margins.

Spikelets in pairs, or clustered at each node. Fertile spikelets pedicelled; 2–10(–25) in the cluster. Pedicels unequal; 0.5–1.5 mm long; ciliate; tip discoid.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; 1.5–2.8 mm long; 0.6–1.2 mm wide; falling entire.

GLUMES Glumes one the lower absent or obscure; shorter than spikelet; thinner than fertile lemma. Upper glume lanceolate; 1.2–2.2 mm long; 0.6–0.95 length of spikelet; membranous; without keels; 3 -veined. Upper glume surface villous. Upper glume apex acute, or acuminate.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate, or elliptic; 1 length of spikelet; membranous; 5–7 -veined; pubescent; hairy between veins, or between veins but central interspaces glabrous; acute, or acuminate. Fertile lemma lanceolate; 1.5–2.8 mm long; cartilaginous; much thinner on margins; keeled. Lemma surface striate. Lemma margins flat; covering most of palea. Lemma apex acute, or acuminate; mucronate. Palea cartilaginous.

DISTRIBUTION Australasia: Australia.

NOTES Paniceae. Webster 1993.

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