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Descriptions

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

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

Helictotrichon cycladum

HABIT Perennial; caespitose; clumped densely. Culms slender; 20–30 cm long. Leaf-sheaths keeled; smooth. Ligule an eciliate membrane; 3–4 mm long; 2–3 mm long on basal shoots; acute. Leaf-blades curved; conduplicate; 2–5 cm long; 1.5–2 mm wide; stiff; pruinose. Leaf-blade venation with subepidermal sclerenchyma free from veins; without layer of subepidermal sclerenchyma masking vein striation. Leaf-blade surface ungrooved; smooth. Leaf-blade margins scaberulous.

INFLORESCENCE Inflorescence a panicle; comprising 4–7 fertile spikelets.

Panicle open; linear, or oblong; 5–7 cm long; bearing few spikelets. Primary panicle branches 1–2 -nate. Panicle branches stiff.

Spikelets solitary. Fertile spikelets sessile, or pedicelled.

FERTILE SPIKELETS Spikelets comprising 3–5 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 15–22 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes pilose; hairy above. Floret callus pilose.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma. Lower glume elliptic; 12 mm long; 0.75 length of upper glume; membranous; 1-keeled; 3 -veined. Lower glume apex acute. Upper glume elliptic; 17 mm long; 1.1 length of adjacent fertile lemma; membranous; 1-keeled; 3–5 -veined. Upper glume apex acute.

FLORETS Fertile lemma elliptic; 15–16 mm long; cartilaginous; without keel; 5–7 -veined. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; geniculate; flat below; 15–20 mm long overall; with twisted column. Palea keels ciliolate. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Anthers 3. Ovary pubescent on apex.

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

DISTRIBUTION Europe: southeastern.

NOTES Aveneae. Fl Eur 1995.

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