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.

Helictotrichon hackelii

HABIT Perennial; caespitose; clumped densely. Basal innovations intravaginal. Culms 40–80 cm long. Leaf-sheath oral hairs ciliate. Ligule an eciliate membrane; 5–8 mm long; 1–1.5 mm long on basal shoots; acute. Leaf-blades aciculate; terete; 20–45 cm long; 0.5–0.7 mm wide; 0.7–2.5 cm long at summit of culm; stiff. Leaf-blade venation with subepidermal sclerenchyma free from veins; with continuous uniform subepidermal sclerenchyma layer on the underside. Leaf-blade surface ungrooved; scabrous. Leaf-blade apex pungent.

INFLORESCENCE Inflorescence a panicle; comprising 7–17 fertile spikelets.

Panicle open; linear, or oblong; 7–20 cm long. Primary panicle branches 2 -nate. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 4–7 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 15–21 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 2–2.5 mm long; pilose; with 2.5–4 mm long hairs. Floret callus pilose. Floret callus hairs 2–3 mm long.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma. Lower glume elliptic; 10–14 mm long; 0.9 length of upper glume; membranous; 1-keeled; 3 -veined. Lower glume apex acute. Upper glume elliptic; 12–18 mm long; 1.1 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma elliptic; 11–17 mm long; cartilaginous; dark brown; without keel; 5–7 -veined. Lemma surface glabrous to pubescent; hairy below. Lemma apex dentate; 2–4 -fid; awned; 3 -awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; geniculate; flat below; 15–20 mm long overall; with twisted column. Lateral lemma awns 1 mm long. 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: southwestern.

NOTES Aveneae. Fl Eur 1995.

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