Helictotrichon setaceum

HABIT Perennial. Basal innovations intravaginal. Culms 20–60 cm long. Culm-internodes distally glabrous. Ligule a ciliolate membrane, or a fringe of hairs; 0.2–0.5 mm long; truncate. Leaf-blades filiform; 10–40 cm long; 0.5–0.8 mm wide. Leaf-blade surface puberulous; hairy adaxially.

INFLORESCENCE Inflorescence a panicle; comprising 8–15 fertile spikelets.

Panicle open; linear, or oblong; dense; 4–10 cm long. Primary panicle branches bearing 2–5 fertile spikelets on each lower branch. Panicle axis smooth.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels linear.

FERTILE SPIKELETS Spikelets comprising 2–3 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 8–12 mm long; breaking up at maturity; disarticulating above glumes but not between florets. Rhachilla internodes 1–2 mm long; pilose; with 4–6 mm long hairs. Floret callus pilose. Floret callus hairs 3–3.5 mm long.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma. Lower glume elliptic; 7–10 mm long; 0.75 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume elliptic; 10–12 mm long; 1.1–1.2 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma elliptic; 8–11 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; subterete below; 12–18 mm long overall; with twisted column. Palea 7–8 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 and southeastern.

NOTES Aveneae. Fl Eur 1995.

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