Digitaria cayoensis

HABIT Annual. Culms erect, or geniculately ascending; 40–80 cm long; without nodal roots, or rooting from lower nodes. Culm-internodes distally glabrous. Lateral branches ample. Leaf-sheaths longer than adjacent culm internode; without keel; hirsute. Ligule an eciliate membrane. Leaf-blades 8–16 cm long; 3–5 mm wide. Leaf-blade surface scabrous; pilose; sparsely hairy; hairy adaxially. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 4–7; digitate, or borne along a central axis; unilateral; 8–12 cm long. Central inflorescence axis 2–8 cm long. Rhachis angular; 0.3 mm wide; scabrous on margins. Raceme-bases brief; pilose.

Spikelets in threes. Fertile spikelets pedicelled. Pedicels unequal; 1–3 mm long; scabrous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; 1.5–1.6 mm long; with hairs extending 0.2 mm beyond apex; falling entire.

GLUMES Glumes one the lower absent or obscure; shorter than spikelet; thinner than fertile lemma. Upper glume oblong; 1.3 mm long; 0.75 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; pubescent; hairy between veins but central interspaces glabrous; acute. Fertile lemma elliptic; 1.4–1.5 mm long; cartilaginous; much thinner on margins; dark brown; without keel. Lemma surface striate. Lemma margins flat; covering most of palea. Lemma apex acute. Palea cartilaginous.

FLOWER Anthers 3.

DISTRIBUTION North America: Mexico. South America: Mesoamericana.

NOTES Paniceae. Henrard 1995.

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