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 arizonica

HABIT Perennial; caespitose; clumped densely. Butt sheaths light brown. Culms erect; 45–90 cm long; wiry. Leaf-sheaths wider than blade at the collar; smooth, or scaberulous; glabrous on surface. Leaf-sheath auricles erect; 0.5–1.5 mm long. Ligule a ciliolate membrane; 0.5–1.5 mm long. Leaf-blades filiform; conduplicate, or involute; 20–50 cm long; 1–1.5 mm wide; glaucous. Leaf-blade surface scabrous; glabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle open, or contracted; linear, or lanceolate; 8–18 cm long. Primary panicle branches appressed, or ascending.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 4–8 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 8–15 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; similar; with lower narrower than upper; shorter than spikelet. Lower glume lanceolate; 5–6.5 mm long; 0.9 length of upper glume; chartaceous; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume surface scabrous; rough at apex. Lower glume apex acute. Upper glume lanceolate; 5–6.5 mm long; 0.9 length of adjacent fertile lemma; chartaceous; without keels; 3 -veined. Upper glume surface scabrous; rough at apex. Upper glume apex acute.

FLORETS Fertile lemma lanceolate; 5.5–7 mm long; chartaceous; without keel; 5 -veined. Lemma apex acute; scabrous; muticous, or mucronate, or awned. Principal lemma awn ascending; 0–2 mm long overall. Palea 2 -veined. Palea keels scabrous. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Anthers 3; 2–3 mm long.

FRUIT Caryopsis with adherent pericarp. Hilum linear.

DISTRIBUTION North America: northwest USA, southwest USA, south-central USA, and Mexico.

NOTES Poeae. Gr Texas 1994.

Please cite this publication as detailed in How to Cite Version: 27th January 2014.