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.

Sesleria rigida

HABIT Perennial; caespitose. Culms erect; 15–45 cm long. Lateral branches lacking. Leaf-sheaths tubular for much of their length; pubescent. Ligule a ciliolate membrane; 0.2–0.4 mm long. Leaf-blades convolute; 1–2 mm wide; 0.5–1 cm long at summit of culm; pruinose. Leaf-blade venation with 7–11 secondary veins; without layer of subepidermal sclerenchyma masking vein striation, or with continuous uniform subepidermal sclerenchyma layer on the underside. Leaf-blade surface pubescent; hairy adaxially.

INFLORESCENCE Inflorescence a panicle. Peduncle tipped by a glumaceous appendage (treated as sterile spikelets).

Panicle capitate; oblong, or ovate; loose; 1.5–3 cm long; 0.7 cm wide. Primary panicle branches accrescent to a central axis.

Spikelets solitary. Fertile spikelets sessile.

STERILE SPIKELETS Basal sterile spikelets represented by a single scale; 2 in number. Basal sterile spikelet glumes membranous.

FERTILE SPIKELETS Spikelets comprising 2 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 5–6 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; similar; reaching apex of florets. Lower glume lanceolate; 5–6 mm long; 1 length of upper glume; membranous; 1-keeled; 1–3 -veined. Lower glume lateral veins absent, or distinct. Lower glume surface glabrous, or pubescent; hairy on veins. Lower glume margins eciliate, or ciliolate. Lower glume apex acute; muticous. Upper glume lanceolate; 5–6 mm long; membranous; 1-keeled; 1–3 -veined. Upper glume lateral veins absent, or distinct. Upper glume surface glabrous, or pubescent; hairy on veins. Upper glume margins eciliate, or ciliate. Upper glume apex acute; muticous.

FLORETS Fertile lemma lanceolate, or ovate; 4–5 mm long; membranous; without keel; 3–5 -veined. Lemma surface glabrous, or pubescent; hairy on veins. Lemma margins ciliate. Lemma apex dentate; 3 -fid; awned; 1–3 -awned. Principal lemma awn 0.5–1.5 mm long overall. Palea 2 -veined. Palea keels ciliolate. Palea apex awned.

FLOWER Anthers 3. Stigmas 2; terminally exserted; pubescent. Ovary pubescent on apex.

FRUIT Caryopsis with adherent pericarp; hairy at apex. Hilum elliptic.

DISTRIBUTION Europe: southeastern.

NOTES Poeae. Deyl 1994.

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