Digitaria fragilis

HABIT Annual. Culms geniculately ascending; 25–80 cm long; without nodal roots, or rooting from lower nodes. Culm-internodes distally glabrous. Culm-nodes glabrous. Lateral branches lacking, or sparse; arising from mid culm. Leaf-sheaths hirsute; with tubercle-based hairs; outer margin hairy. Ligule a ciliolate membrane. Leaf-blades 10–12 cm long; 3 mm wide. Leaf-blade midrib prominent beneath. Leaf-blade surface hirsute; densely hairy; hairy on both sides; with tubercle-based hairs. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 2–10; borne along a central axis; unilateral; 10–12 cm long; simple, or with branchlets at base of longer racemes; secondary branches racemulose. Central inflorescence axis 3 cm long; villous. Rhachis angular; scabrous on margins; villous on margins. Raceme-bases hirsute.

Spikelets in threes, or clustered at each node. Fertile spikelets pedicelled; 3–4 in the cluster. Pedicels angular; unequal; scaberulous; puberulous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; acute; 1.5–1.6 mm long; falling entire.

GLUMES Glumes one the lower absent or obscure; shorter than spikelet; thinner than fertile lemma. Upper glume lanceolate; 0.9 length of spikelet; narrower than lemma; membranous; without keels; 3 -veined. Upper glume surface pilose; hairy between veins. Upper glume hairs yellow. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret elliptic; 1 length of spikelet; membranous; 5 -veined; puberulous; hairy between veins but central interspaces glabrous; acute. Fertile lemma elliptic; 1.4–1.5 mm long; cartilaginous; much thinner on margins; red; without keel. Lemma surface striate. Lemma margins flat; covering most of palea. Lemma apex apiculate. Palea cartilaginous.

FLOWER Anthers 3.

DISTRIBUTION South America: northern South America, western South America, and Brazil.

NOTES Paniceae. Henrard 1996.

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