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 pseudoracemosus

HABIT Perennial; culms solitary. Rhizomes elongated. Butt sheaths persistent and investing base of culm; with fibrous dead sheaths. Culms erect; 60–90 cm long; 5–6 mm diam.; 2–3 -noded. Culm-internodes distally pubescent. Leaf-sheaths longer than adjacent culm internode; glabrous on surface. Ligule an eciliate membrane; 3 mm long. Leaf-blades flat, or involute; 15–40 cm long; 5–7 mm wide; coriaceous; stiff; grey-green. Leaf-blade surface smooth, or scaberulous; rough on both sides; puberulous to hirsute; hairy adaxially.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; linear; bilateral; 12–25 cm long; 20–30 mm wide; with branchlets at base of longer racemes; secondary branches racemulose (3–4cm long). Rhachis pubescent on surface; ciliate on margins. Spikelet packing broadside to rhachis. Rhachis internodes linear; 2.5–10 mm long.

Spikelets in threes, or clustered at each node. Fertile spikelets sessile; 3–5 in the cluster.

FERTILE SPIKELETS Spikelets comprising 5–10 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 13–20 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 1–1.8 mm long; pubescent. Floret callus pilose. Floret callus hairs 1–1.5 mm long.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 10–12 mm long; 0.75 length of upper glume; coriaceous; much thinner on margins; 3 -veined. Lower glume lateral veins obscure. Lower glume margins ciliate. Lower glume apex acuminate; awned; 1 -awned. Lower glume awn 1–1.7 mm long. Upper glume lanceolate; 13–16 mm long; 1.2–1.7 length of adjacent fertile lemma; coriaceous; with membranous margins; without keels; 3 -veined. Upper glume lateral veins obscure. Upper glume margins ciliate. Upper glume apex acuminate; awned; 1 -awned. Upper glume awn 1–1.7 mm long.

FLORETS Fertile lemma lanceolate; 9–13 mm long; coriaceous; much thinner on margins; without keel; 5–7(–10) -veined. Lemma lateral veins obscure. Lemma surface pilose. Lemma margins ciliate. Lemma hairs 1 mm long. Lemma apex acuminate; mucronate, or awned; 1 -awned. Principal lemma awn 0.2–1.5 mm long overall. Palea 1 length of lemma; 2 -veined. Palea keels ciliate; adorned above. Palea surface pilose; hairy on margins. Palea apex dentate; 2 -fid. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Anthers 3; 3–5 mm long; yellow.

FRUIT Caryopsis with adherent pericarp; ellipsoid; 4.5–5 mm long; dark brown; hairy at apex.

DISTRIBUTION Asia-temperate: China.

NOTES Triticeae. Yen & Yang 1996.

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