GrassBase - The Online World Grass Flora

Descriptions

W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Festuca tibestica

HABIT Perennial; caespitose; clumped loosely. Butt sheaths persistent and investing base of culm; with compacted dead sheaths. Culms erect; 15–30 cm long; 2–3 -noded. Culm-internodes smooth. Leaf-sheaths 5–15 cm long; smooth; glabrous on surface. Ligule an eciliate membrane; 1 mm long; truncate. Leaf-blades linear; conduplicate; 5–10 cm long; 2–4 mm wide. Leaf-blade venation comprising 7 vascular bundles; with 7 inner ridges; with sclerenchyma strands below veins and above all veins; with subepidermal sclerenchyma strands similar in size; with subepidermal sclerenchyma free from veins; without layer of subepidermal sclerenchyma masking vein striation. Leaf-blade surface ribbed; grooved adaxially; smooth, or scaberulous; rough adaxially; glabrous.

INFLORESCENCE Inflorescence a panicle; without bracts, or bracteate at pedicel base.

Panicle open; lanceolate; dense; 5–16 cm long; 1 cm wide. Primary panicle branches appressed; 1–3 cm long; bearing 5–8 fertile spikelets on each lower branch. Panicle branches scaberulous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 0.7–0.9 mm long.

FERTILE SPIKELETS Spikelets comprising 3 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 8–11 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 7.6–8.5 mm long; 0.9 length of upper glume; chartaceous; much thinner above; without keels; 3 -veined. Lower glume lateral veins distinct. Lower glume surface scabrous. Lower glume apex acuminate. Upper glume oblong; 7.5–8.5 mm long; 1 length of adjacent fertile lemma; chartaceous; much thinner above; without keels; 5 -veined. Upper glume surface scabrous.

FLORETS Fertile lemma lanceolate; 7.5–8.5 mm long; 2 mm wide; chartaceous; much thinner above; without keel; 5 -veined. Lemma lateral veins obscure. Lemma surface scabrous; rough on veins. Lemma apex acute; mucronate. Palea lanceolate; 5–6 mm long; 2 -veined. Palea apex dentate; 2 -fid. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2. Anthers 3. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp; oblong; 5 mm long. Hilum linear.

DISTRIBUTION Africa: northeast tropical.

NOTES Poeae. Mire 2005.

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