Digitaria insularis

HABIT Perennial; caespitose. Rootstock evident. Butt sheaths pubescent. Culms erect, or geniculately ascending; 70–120 cm long; 5–10 mm diam. Culm-nodes brown; bearded. Ligule an eciliate membrane; 2–4 mm long. Leaf-blades 12–40 cm long; 7–15 mm wide. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes numerous; 20–50; borne along a central axis; unilateral; 10–15 cm long. Central inflorescence axis 8–30 cm long. 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 lanceolate; dorsally compressed; acuminate; 3.5–4 mm long; falling entire. Rhachilla internodes elongated below basal sterile floret.

GLUMES Glumes two; dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume oblong; 0.5–1 mm long; 0.15–0.25 length of spikelet; hyaline; without keels; 0 -veined. Lower glume lateral veins absent. Lower glume apex truncate. Upper glume lanceolate; 1 length of spikelet; membranous; without keels; 3 -veined. Upper glume surface villous. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate; 1 length of spikelet; membranous; 7 -veined; villous; acuminate. Fertile lemma lanceolate; 3–3.5 mm long; cartilaginous; much thinner on margins; dark brown; without keel. Lemma margins flat; covering most of palea. Lemma apex acute. Palea cartilaginous.

DISTRIBUTION Asia-temperate: eastern Asia. Asia-tropical: Malesia and Papuasia. Pacific: south-central, northwestern, and north-central. North America: southwest USA, south-central USA, southeast USA, and Mexico. South America: Mesoamericana, Caribbean, northern South America, western South America, Brazil, and southern South America.

NOTES Paniceae. Gr Bahia.

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