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 alba

HABIT Perennial; caespitose. Butt sheaths thickened and forming a bulb; persistent and investing base of culm; with compacted dead sheaths. Culms erect; 10–40 cm long. Leaf-sheaths pubescent. Ligule an eciliate membrane; 1–1.5 mm long. Leaf-blades 12–20 cm long; 3–5 mm wide; light green, or glaucous. Leaf-blade surface glabrous. Leaf-blade margins smooth, or scaberulous. Leaf-blade apex acute, or acuminate.

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

Panicle capitate; oblong; 3–8.5 cm long; 0.5–0.8 cm wide. Primary panicle branches accrescent to a central axis; with evident branchlets on axis, or with lateral stumps on axis.

Spikelets solitary. Fertile spikelets pedicelled.

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

FERTILE SPIKELETS Spikelets comprising 2–3 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 6–9 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; similar; reaching apex of florets. Lower glume lanceolate; 6–9 mm long; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein ciliolate. Lower glume lateral veins absent. Lower glume apex acuminate; awned; 1 -awned. Lower glume awn 1–2 mm long. Upper glume lanceolate; 6–9 mm long; 1.1–1.5 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume primary vein ciliolate. Upper glume lateral veins absent. Upper glume apex acuminate; awned; 1 -awned. Upper glume awn 1–2 mm long.

FLORETS Fertile lemma elliptic, or oblong; 5.5–6 mm long; membranous; without keel; rounded except near apex; 3–5 -veined. Lemma apex dentate; 3–5 -fid; awned; 3–5 -awned. Principal lemma awn 1–1.7 mm long overall. Lateral lemma awns arising on apex of lobes; shorter than principal. Palea 1 length of lemma; 2 -veined. Palea keels pubescent. Palea apex dentate; 2 -fid; awned; awns 0.2–0.5 mm long.

FLOWER Anthers 3; 3–4 mm long; yellow. Stigmas 2; terminally exserted. Ovary pubescent all over.

FRUIT Caryopsis with adherent pericarp; 2 mm long; hairy all over. Hilum punctiform.

DISTRIBUTION Europe: southeastern and eastern. Asia-temperate: western Asia.

NOTES Poeae. Fl Turk 1993.

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