GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Leymus mollis

HABIT Perennial; culms solitary, or caespitose; clumped loosely. Rhizomes elongated; scaly. Butt sheaths light brown; persistent and investing base of culm; with fibrous dead sheaths. Culms erect; robust; 30–100 cm long; 3–4 mm diam.; 3–4 -noded. Culm-internodes terete; distally glabrous. Leaves mostly basal. Leaf-sheaths loose; 7–25 cm long; glabrous on surface. Ligule an eciliate membrane; 1–3 mm long; truncate. Leaf-blades involute; 14–45 cm long; 6–12 mm wide; stiff; glaucous. Leaf-blade surface ribbed; scaberulous; rough adaxially. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes. Peduncle pubescent above.

Racemes 1; single; erect; bilateral; 9–25 cm long; 12–22 mm wide. Rhachis flattened; pubescent on surface; scabrous on margins. Spikelet packing broadside to rhachis; regular; 2 -rowed. Rhachis internodes 5–20 mm long.

Spikelets appressed; in pairs, or in threes. Fertile spikelets sessile; 2–3(–5) in the cluster.

FERTILE SPIKELETS Spikelets comprising 3–5 fertile florets; with diminished florets at the apex. Spikelets elliptic; laterally compressed; 15–22 mm long; 5–7 mm wide; breaking up at maturity; disarticulating below each fertile floret. Spikelet callus glabrous; base truncate. Rhachilla internodes 2–3 mm long; pubescent.

GLUMES Glumes persistent; similar; subequal in width; reaching apex of florets. Lower glume lanceolate; 14–22 mm long; 1 length of upper glume; coriaceous; 1-keeled; (3–)5 -veined. Lower glume surface pubescent. Lower glume apex attenuate. Upper glume lanceolate; 14–22 mm long; 1.2–1.3 length of adjacent fertile lemma; coriaceous; 1-keeled; (3–)5 -veined. Upper glume surface pubescent. Upper glume apex attenuate.

FLORETS Fertile lemma lanceolate; 12–17 mm long; 3–4 mm wide; chartaceous; keeled; keeled above; 5 -veined. Lemma surface pubescent. Lemma apex acute. Palea 10–13 mm long; 2 -veined. Palea keels ciliate. Palea surface pubescent. Palea apex dentate; 2 -fid. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; elliptic; membranous. Anthers 3; 6–7 mm long. Stigmas 2. Ovary pubescent on apex.

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

DISTRIBUTION Asia-temperate: Soviet far east, China, and eastern Asia. North America: Subarctic, western Canada, eastern Canada, northwest USA, north-central USA, northeast USA, and southwest USA.

NOTES Triticeae. Koyama 1997.

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