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 horizontalis

HABIT Annual. Culms decumbent; 20–100 cm long. Ligule an eciliate membrane. Leaf-blades 2–20 cm long; 2–14 mm wide.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 4–22; borne along a central axis; unilateral; 4–17 cm long. Central inflorescence axis 1–6 cm long. Rhachis narrowly winged; angular; glabrous on surface, or with scattered hairs; scabrous on margins. Spikelet packing lax; 0.5 their length apart.

Spikelets appressed; in pairs. Fertile spikelets pedicelled; 2 in the cluster; all alike.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; acute; 1.7–3 mm long; falling entire.

GLUMES Glumes one the lower absent or obscure, or two; dissimilar; shorter than spikelet; thinner than fertile lemma. Lower glume ovate; 0–0.15 mm long; 0.1 length of spikelet. Upper glume lanceolate; 0.3–0.5 length of spikelet; membranous; without keels; 3 -veined. Upper glume surface pubescent; hairy between veins. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret elliptic; 1 length of spikelet; membranous; 7 -veined; with equidistant veins, or with unevenly spaced veins; puberulous, or pubescent; hairy between veins; eciliate on margins, or ciliate on margins; acute. Fertile lemma elliptic; 1.7–3 mm long; cartilaginous; much thinner on margins; grey, or dark brown; without keel; 3 -veined. Lemma margins flat; covering most of palea; ciliate. Palea cartilaginous.

DISTRIBUTION Africa: Macaronesia, west tropical, west-central tropical, northeast tropical, and western Indian ocean. Asia-temperate: Caucasus. Asia-tropical: Indo-China. Pacific: southwestern, south-central, and north-central. North America: southeast USA and Mexico. South America: Mesoamericana, Caribbean, northern South America, western South America, Brazil, and southern South America.

NOTES Paniceae. WDC.

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