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 geminatus

HABIT Perennial; caespitose. Culms erect, or geniculately ascending; 75–100 cm long; 2–3 mm diam.; 2–5 -noded; with 0.2–0.5 of their length below uppermost node. Culm-internodes smooth; distally glabrous. Leaf-sheaths smooth; glabrous on surface. Ligule an eciliate membrane; 1 mm long; scarious; truncate. Leaf-blades 7.5–27 cm long; 3–5 mm wide. Leaf-blade surface puberulous; hairy adaxially. Leaf-blade margins ciliate.

INFLORESCENCE Inflorescence composed of racemes. Peduncle pubescent above.

Racemes 1; single; drooping; arcuate; bilateral; 8–15 cm long; bearing 15–24 fertile spikelets on each; simple, or with branchlets at base of longer racemes. Rhachis flattened; puberulous on surface. Spikelet packing broadside to rhachis; regular; 2 -rowed. Rhachis internodes 2–5 mm long.

Spikelets solitary, or in pairs. Fertile spikelets sessile, or sessile and pedicelled; 1–2 in the cluster. Pedicels 0.5–1 mm long.

FERTILE SPIKELETS Spikelets comprising 5–7 fertile florets; with diminished florets at the apex. Spikelets laterally compressed; 16–20 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 1.5 mm long; pubescent. Floret callus pubescent.

GLUMES Glumes persistent; similar; subequal in width; shorter than spikelet. Lower glume lanceolate; 5–8 mm long; coriaceous; purple; without keels; 3 -veined. Lower glume surface pubescent. Lower glume apex acuminate; muticous, or mucronate. Upper glume lanceolate; 6–8 mm long; coriaceous; purple; without keels; 3–5 -veined. Upper glume surface pubescent. Upper glume apex acuminate; muticous, or mucronate.

FLORETS Fertile lemma lanceolate, or oblong; 9.5–10.5 mm long; coriaceous; purple; without keel; 5 -veined. Lemma apex awned; 1 -awned. Principal lemma awn straight, or curved; 5–11 mm long overall. Palea 1 length of lemma; 2 -veined. Palea keels ciliate; with hairs 0.6–1.2 mm long. Palea surface puberulous; hairy on back. Palea apex truncate. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; oblong; 2 mm long; membranous; ciliate. Anthers 3; 2 mm long; brown, or purple. Stigmas 2. Ovary pubescent on apex.

FRUIT Caryopsis with adherent pericarp; hairy at apex; apex unappendaged. Hilum linear.

DISTRIBUTION Asia-temperate: China.

NOTES Triticeae. Chen 2001.

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