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.

Elymus yukonensis

HABIT Perennial; mat forming. Rhizomes elongated. Culms 20–50 cm long. Culm-nodes glabrous. Leaf-sheaths puberulous. Ligule an eciliate membrane; 0.4–0.5 mm long; entire, or erose. Leaf-blades 2–5 cm long; 1–4 mm wide; coriaceous; stiff; glaucous. Leaf-blade surface ribbed; puberulous; hairy adaxially.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; bilateral; 4–10 cm long. Rhachis flattened. Spikelet packing broadside to rhachis. Rhachis internodes linear. Rhachis internode tip flat.

Spikelets solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 3–5 fertile florets; with diminished florets at the apex. Spikelets elliptic to oblong; laterally compressed; 9–12 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes collateral; persistent; similar; shorter than spikelet. Lower glume lanceolate; 5–6 mm long; 1 length of upper glume; coriaceous; without keels; 2–4 -veined. Lower glume lateral veins ribbed. Lower glume apex acute. Upper glume lanceolate; 5–6 mm long; 1 length of adjacent fertile lemma; coriaceous; without keels; 2–4 -veined. Upper glume lateral veins ribbed. Upper glume apex acute.

FLORETS Fertile lemma lanceolate to oblong; 7–10 mm long; coriaceous; 5–7 -veined. Lemma surface pilose. Lemma apex acute; muticous, or awned; 1 -awned. Principal lemma awn 0–10 mm long overall. Palea 1 length of lemma. Palea keels scabrous. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; membranous. Anthers 3; 3–5 mm long. Stigmas 2. Ovary pubescent on apex.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION North America: Subarctic.

NOTES Triticeae. Fl Alaska 1994.

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