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 laxa

HABIT Perennial; caespitose; clumped loosely. Culms geniculately ascending, or leaning; 100–200 cm long; 3–5 mm diam. Culm-internodes smooth; distally glabrous. Leaf-sheaths inflated (slightly); glabrous on surface, or hispid; with tubercle-based hairs. Ligule an eciliate membrane; 1.5–3 mm long. Leaf-blades lanceolate; 12–25 cm long; 10–15 mm wide. Leaf-blade surface glabrous.

INFLORESCENCE Inflorescence composed of racemes. Peduncle 6–30 cm long; glabrous.

Racemes numerous; borne along a central axis; in several whorls; unilateral; 10–18 cm long. Central inflorescence axis 15–30 cm long. Rhachis angular; scabrous on margins.

Spikelets appressed; in pairs. Fertile spikelets pedicelled. Pedicels unequal.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 4.2–5.3 mm long; with hairs extending 0 mm beyond apex; falling entire. Rhachilla internodes elongated below proximal fertile floret. Rhachilla elongation 0.4 mm long.

GLUMES Glumes two; shorter than spikelet; thinner than fertile lemma. Lower glume elliptic; 0.5–0.6 mm long; 0.1 length of spikelet; 0 -veined. Lower glume lateral veins absent. Upper glume linear; 2–2.5 mm long; 0.5 length of spikelet; membranous; without keels; 1 -veined. Upper glume lateral veins absent. Upper glume surface pilose. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate; 1 length of spikelet; membranous; 5–7 -veined; pubescent; scabrous on margins; ciliate on margins; bearing tawny hairs; acute. Fertile lemma lanceolate; 3.2–3.7 mm long; cartilaginous; much thinner on margins; light brown, or dark brown; without keel. Lemma margins flat; covering most of palea. Palea cartilaginous.

DISTRIBUTION South America: Caribbean, northern South America, Brazil, and southern South America.

NOTES Paniceae. Fl Guiana 1995.

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