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 yvesii

HABIT Perennial; caespitose; clumped densely. Butt sheaths persistent and investing base of culm; with compacted dead sheaths. Basal innovations intravaginal. Culms 25–48 cm long. Culm-internodes distally glabrous. Leaf-sheaths open for most of their length; with 0.25–0.33 of their length closed; with flat margins; glabrous on surface. Leaf-sheath auricles erect; obtuse. Ligule an eciliate membrane. Leaf-blades curved; filiform; conduplicate; circular in section; 0.6–1.2 mm wide; stiff; light green, or glaucous; without exudate, or pruinose. Leaf-blade venation comprising 7–9 vascular bundles; with 1 inner ridges; with subepidermal sclerenchyma free from veins; with continuous uniform subepidermal sclerenchyma layer on the underside. Leaf-blade apex acute; pungent.

INFLORESCENCE Inflorescence a panicle.

Panicle open; dense; 3–6 cm long. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 3–4 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 8–10 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes obscured by lemmas.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; chartaceous; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate; 4.5–5.7 mm long; 0.7–0.8 length of adjacent fertile lemma; chartaceous; without keels; 3 -veined. Upper glume apex acuminate.

FLORETS Fertile lemma oblong; 5.5–7.1 mm long; chartaceous; glaucous; without keel; 5 -veined. Lemma margins eciliate, or ciliate; hairy above. Lemma apex acuminate; awned; 1 -awned. Principal lemma awn 2.5–3.5 mm long overall. Palea 2 -veined. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Anthers 3.

FRUIT Caryopsis with adherent pericarp; ellipsoid. Hilum linear. Disseminule comprising a caryopsis and palea.

DISTRIBUTION Europe: southwestern.

NOTES Poeae. Fl Eur 1995.

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