Festuca costata

HABIT Perennial; caespitose. Butt sheaths persistent and investing base of culm; with fibrous dead sheaths. Culms 60–100 cm long; 1–3 -noded. Leaf-sheaths smooth; glabrous on surface. Ligule an eciliate membrane; 1–4 mm long. Leaf-blades convolute; 15–50 cm long; 2–4 mm wide. Leaf-blade surface smooth. Leaf-blade margins scaberulous. Leaf-blade apex attenuate; filiform.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; effuse; 10–20 cm long. Primary panicle branches 2 -nate. Panicle branches flexuous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 3–6 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 10–20 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 3.5–6.5 mm long; 0.8–0.9 length of upper glume; chartaceous; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate; 4–8 mm long; 0.6–0.8 length of adjacent fertile lemma; chartaceous; without keels; 3 -veined. Upper glume apex acute.

FLORETS Fertile florets divergent. Fertile lemma elliptic; 6.5–10 mm long; coriaceous; without keel; 5 -veined. Lemma surface scaberulous; puberulous. Lemma apex obtuse; muticous, or mucronate. Principal lemma awn subapical. Palea 1 length of lemma; 2 -veined. Palea keels scaberulous. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2. Anthers 3; 3.5 mm long. Ovary glabrous, or pubescent on apex.

FRUIT Caryopsis with adherent pericarp; glabrous, or hairy at apex. Hilum linear.

DISTRIBUTION Africa: east tropical, southern tropical, and south.

NOTES Poeae. FTEA.

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