Digitaria thouarsiana (Flüggé) A.Camus

Gramineae, W. D. Clayton, S. M. Phillips & S. A. Renvoize. Flora of Tropical East Africa. 1974

Morphology General Habit

Tufted annual; culms 20–100 cm. high, ascending.

Morphology Leaves

Leaf-blades 3–20 cm. long, 2–8 mm. wide.

Morphology Reproductive morphology Inflorescences

Inflorescence of 2–14 subdigitate racemes; racemes 2–12 cm. long, the spikelets in clusters of 3–4 on a ribbon-like winged rhachis with rounded or shallowly angular midrib; pedicels scaberulous or with a few short hairs at the tip, rarely with a definite corona of hairs.

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets elliptic, 1–1.7 mm. long; lower glume absent; upper glume 1/2–4/5 as long as the spikelet, 3-nerved, shortly pubescent with clavate hairs, rarely glabrous; lower lemma as long as the spikelet, 5-nerved, the 3 central nerves close together, mealy pubescent on the outer side of the nerves or all over, rarely glabrous, the hairs clavate and short (up to 0.1 mm.), the lemma-tip visible; fruit elliptic, dorsally flattened, dark brown to black.

Habitat

Marshy places and disturbed sites; 0–2400 m.

Distribution

K3 K4 K5 T1 T2 T3 T6 T7 U1 U2 U3 U4 Z

Morphology General Habit

Annual; caespitose. Culms geniculately ascending; 20-100 cm long. Ligule an eciliate membrane. Leaf-blades 3-20 cm long; 2-8 mm wide.

Morphology Reproductive morphology Inflorescences

Inflorescence composed of racemes. Racemes 2-14; digitate; unilateral; 2-12 cm long. Rhachis broadly winged; with rounded midrib, or sharp-edged midrib. Spikelets in threes, or clustered at each node. Fertile spikelets pedicelled; 3-4 in the cluster. Pedicels unequal; scaberulous; glabrous, or puberulous; hairy at tip.

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; 1-1.7 mm long; with hairs extending 0 mm beyond apex; falling entire.

Fertile

Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; 1-1.7 mm long; with hairs extending 0 mm beyond apex; falling entire.

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes one the lower absent or obscure; shorter than spikelet; thinner than fertile lemma. Upper glume elliptic; 0.5-0.8 length of spikelet; membranous; without keels; 3 -veined. Upper glume surface glabrous, or pubescent; with clavate hairs. Upper glume apex acute.

Morphology Reproductive morphology Flowers Florets

Basal sterile florets barren; without significant palea. Lemma of lower sterile floret elliptic; 1 length of spikelet; membranous; 5 -veined; with unevenly spaced veins (3 central veins approximate); glabrous, or puberulous (mealy); hairy between veins (generally or in stripes); with clavate hairs; bearing hairs 0.05-0.1 mm long; acute. Fertile lemma elliptic; 1-1.7 mm long; cartilaginous; much thinner on margins; dark brown, or black; without keel. Lemma margins flat; covering most of palea. Lemma apex acute. Palea cartilaginous.

Morphology Reproductive morphology Fruits

Caryopsis flattened.

Distribution

Africa: west-central tropical, east tropical, southern tropical, south, and western Indian ocean.

Reference

Paniceae. FTEA.

Gramineae, W. D. Clayton. Flora Zambesiaca 10:3. 1989

Morphology General Habit

A loosely caespitose annual.

Morphology Culms

Culms 20–40(80) cm., erect, glabrous, nodes dark and glabrous.

Morphology Leaves Leaf sheaths

Leaf sheaths glabrous.

Morphology Leaves Ligules

Ligule c. 2 mm. long, rounded triangular, entire.

Morphology Leaves Leaf lamina

Leaf laminae 3–20 × 0.2–0.6 cm., linear, flat, glabrous, sometimes scaberulous on both surfaces, basally often with a few bulbous-based bristles, scaberulous along the margin.

Morphology Reproductive morphology Inflorescences

Inflorescence of 3–7 racemes, 7–15 cm. long, a few together or all solitary along a short common axis, often pseudoviviparous.

Morphology Leaves Rachis

Rhachis triquetrous, broadly winged, up to 1 mm. broad, smooth with scabrous margins.

Morphology Reproductive morphology Flowers Pedicel

Pedicels 3-nate, 0.5–2.5 mm. long, terete to compressed, minutely scaberulous, broadened at the apex, bearing a poorly developed coronula with cilia up to 0.3 trim. long.

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets 1.2–1.8 mm. long, ovate.

Morphology Reproductive morphology Inflorescences Bracts Glume

Inferior glume absent. Superior glume 1/3–4/5 of the spikelet in length, ovate-oblong, 3-nerved, hyaline, glabrous or appressed hairy, hairs white, capitate-apiculate.

Inferior

Inferior glume absent. Inferior lemma as long as the spikelet, ovate with recurved margins, 5-nerved, hyaline, glabrous or appressed hairy.

Morphology Reproductive morphology Inflorescences Bracts Lemma

Superior lemma as long as the spikelet, ovate, apiculate, dark brown. Inferior lemma as long as the spikelet, ovate with recurved margins, 5-nerved, hyaline, glabrous or appressed hairy.

Superior

Superior lemma as long as the spikelet, ovate, apiculate, dark brown. Superior glume 1/3–4/5 of the spikelet in length, ovate-oblong, 3-nerved, hyaline, glabrous or appressed hairy, hairs white, capitate-apiculate.