Digitaria rivae

HABIT Perennial; caespitose. Rhizomes short; knotty. Butt sheaths pubescent, or woolly. Culms 30–100 cm long; firm (hard). Culm-nodes glabrous, or bearded (rarely). Ligule an eciliate membrane. Leaf-blades 4–30 cm long; 2–5 mm wide.

INFLORESCENCE Inflorescence composed of racemes.

Racemes few, or numerous; 6–40; borne along a central axis; simply spaced, or the lowest whorled; spreading, or appressed; unilateral; 1–11 cm long. Central inflorescence axis 4–30 cm long (glabrous). Rhachis wingless; angular.

Spikelets in pairs. Fertile spikelets pedicelled; 2 in the cluster. Pedicels unequal.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets ovate; dorsally compressed; 1.7–2.5 mm long; with hairs extending 0.5 mm beyond apex; falling entire.

GLUMES Glumes two; dissimilar; shorter than spikelet; thinner than fertile lemma. Lower glume ovate; 0.1–0.6 mm long; 0.05–0.25 length of spikelet; membranous; without keels. Lower glume apex obtuse. Upper glume ovate; 0.66–0.8 length of spikelet; membranous; without keels; 3(–5) -veined. Upper glume surface pubescent, or pilose. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret ovate; 1 length of spikelet; membranous; 5–7 -veined; pilose, or villous; acute. Fertile lemma elliptic; 1.7–2.5 mm long; cartilaginous; much thinner on margins; light brown; without keel. Lemma margins flat; covering most of palea. Lemma apex acute. Palea cartilaginous.

DISTRIBUTION Africa: northeast tropical and east tropical.

NOTES Paniceae. FTEA.

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