Helictotrichon requienii

HABIT Perennial; caespitose. Rhizomes short. Culms robust; 60–100 cm long. Ligule an eciliate membrane; 6–10 mm long; 1.4–4.5 mm long on basal shoots; acute. Leaf-blades terete; 30–50 cm long; 1.2–1.3 mm wide; stiff. Leaf-blade venation with 8–10 secondary veins; without layer of subepidermal sclerenchyma masking vein striation. Leaf-blade surface ungrooved. Leaf-blade apex acute.

INFLORESCENCE Inflorescence a panicle; comprising 14–17 fertile spikelets.

Panicle open; linear, or oblong; 15–20 cm long. Primary panicle branches bearing 2–3 fertile spikelets on each lower branch. 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; 16–23 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 2.5–3 mm long; pilose; with 2–2.5 mm long hairs. Floret callus pilose.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma. Lower glume elliptic; 13 mm long; 0.75 length of upper glume; membranous; 1-keeled; 3 -veined. Lower glume apex acute. Upper glume elliptic; 17 mm long; 1.1–1.2 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma elliptic; 14–16 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: southwestern.

NOTES Aveneae. Fl Eur 1995.

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