Digitaria dioica

HABIT Perennial; caespitose. Butt sheaths thickened and forming a bulb; pilose; persistent and investing base of culm; with fibrous dead sheaths. Culms erect; 45–85(–100) cm long. Leaves mostly basal. Ligule an eciliate membrane. Leaf-blades flat, or involute; 10–60 cm long; 2–4(–7) mm wide. Leaf-blade surface glabrous, or pubescent. Leaf-blade apex acuminate.

INFLORESCENCE Dioecious. Inflorescence composed of racemes.

Racemes 3–8; digitate, or borne along a central axis; unilateral; 3–12(–23) cm long; with branchlets at base of longer racemes; secondary branches racemulose (1–2cm). Central inflorescence axis 2–15 cm long. Rhachis angular.

Spikelets clustered at each node. Fertile spikelets pedicelled; 3–10 in the cluster. Pedicels unequal.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; 2.8–3.8 mm long; falling entire.

GLUMES Glumes two; dissimilar; shorter than spikelet; thinner than fertile lemma. Lower glume oblate; 0.5 mm long; 0.15 length of spikelet; hyaline; without keels; 0 -veined. Lower glume lateral veins absent. Lower glume apex truncate. Upper glume lanceolate; 0.5–0.75 length of spikelet; membranous; without keels; 3 -veined. Upper glume surface pilose. Upper glume apex acuminate.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate; 1 length of spikelet; membranous; 5–7 -veined; pilose; acuminate. Fertile florets female. Fertile lemma lanceolate; 2.5–3.5 mm long; cartilaginous; much thinner on margins; yellow; without keel. Lemma margins flat; covering most of palea. Lemma apex acute. Palea cartilaginous.

MALE Male inflorescence similar to female. Male spikelets resembling female.

DISTRIBUTION South America: western South America and Brazil.

NOTES Paniceae. Gr Bolivia 1997.

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