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 viridula

HABIT Perennial; caespitose; clumped loosely. Butt sheaths persistent and investing base of culm; with fibrous dead sheaths. Culms erect; 40–80 cm long. Leaf-sheaths striately veined; glabrous on surface, or pubescent. Ligule an eciliate membrane; 0.5 mm long. Leaf-blades conduplicate; 5–10 cm long; 1.5–2.5 mm wide. Leaf-blade surface puberulous; hairy adaxially.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 6–15 cm long. Primary panicle branches ascending, or spreading; 2 -nate.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 3–7 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 10–12 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 1–1.5 mm long; eventually visible between lemmas.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 2.5–5 mm long; 0.5–0.75 length of upper glume; membranous; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate; 4.5–7 mm long; 0.75 length of adjacent fertile lemma; membranous; without keels; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma elliptic; 6–8.5 mm long; chartaceous; without keel; 5 -veined. Lemma surface scaberulous. Lemma apex acute; muticous, or mucronate. Palea 1 length of lemma; 2 -veined. Palea keels scaberulous. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2. Anthers 3; 2–4 mm long. Ovary pubescent on apex.

FRUIT Caryopsis with adherent pericarp. Hilum linear.

DISTRIBUTION North America: western Canada, northwest USA, and southwest USA.

NOTES Poeae. Fl Pac NW 1993.

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