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.

Elymus rigidulus

HABIT Perennial; caespitose; clumped loosely. Culms erect, or geniculately ascending; 50–75 cm long; 2 mm diam.; 3–4 -noded; with 0.4–0.5 of their length below uppermost node. Leaf-sheaths 15–17 cm long; mostly shorter than adjacent culm internode; glabrous on surface. Ligule an eciliate membrane; 0.4 mm long; scarious. Leaf-blades erect; involute; 3–10 cm long; 2–4 mm wide. Leaf-blade surface pubescent; hairy adaxially. Leaf-blade margins ciliate.

INFLORESCENCE Inflorescence composed of racemes. Peduncle glabrous.

Racemes 1; single; arcuate; bilateral; 7.5–8 cm long. Rhachis flattened; glabrous on margins, or ciliate on margins. Spikelet packing broadside to rhachis; regular; 2 -rowed. Rhachis internodes 3–9 mm long.

Spikelets solitary. Fertile spikelets sessile.

STERILE SPIKELETS Basal sterile spikelets absent, or rudimentary; 1 in number.

FERTILE SPIKELETS Spikelets comprising 4–6 fertile florets; with diminished florets at the apex. Spikelets laterally compressed; 10–15 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 1 mm long; pubescent. Floret callus pubescent.

GLUMES Glumes persistent; similar; subequal in width; shorter than spikelet. Lower glume lanceolate, or ovate; 2–4 mm long; coriaceous; without keels; 1–4 -veined. Lower glume primary vein scabrous. Lower glume surface glabrous. Lower glume apex acute, or acuminate; muticous. Upper glume lanceolate, or oblong; 3–5 mm long; coriaceous; without keels; 3–4 -veined. Upper glume primary vein scabrous. Upper glume surface glabrous. Upper glume apex acuminate; muticous.

FLORETS Fertile lemma lanceolate, or oblong; 7–8 mm long; coriaceous; without keel; 5 -veined. Lemma surface pubescent, or pilose. Lemma apex awned; 1 -awned. Principal lemma awn 2–3 mm long overall. Palea 1 length of lemma; 2 -veined. Palea keels ciliolate; adorned above; with 0.8 of their length adorned. Palea surface puberulous; hairy on back. Palea apex emarginate. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; membranous. Anthers 3; 2–2.5 mm long; yellow, 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.