Helictotrichon agropyroides

HABIT Perennial. Rhizomes elongated. Butt sheaths persistent and investing base of culm; with compacted dead sheaths. Basal innovations extravaginal. Culms erect; 50–90 cm long. Ligule an eciliate membrane; 3–6 mm long; acute. Leaf-blades 1.7–2.6 mm wide; stiff. Leaf-blade midrib prominent beneath. Leaf-blade surface glabrous. Leaf-blade margins scabrous.

INFLORESCENCE Inflorescence a panicle; comprising 5–15 fertile spikelets.

Panicle open; lanceolate; 10–22 cm long.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 1–6 mm long; scaberulous.

FERTILE SPIKELETS Spikelets comprising 5–10 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 15–34 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes glabrous, or pubescent; hairy above. Floret callus pilose. Floret callus hairs 2 mm long.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma. Lower glume elliptic; 15 mm long; 0.75 length of upper glume; membranous; 1-keeled; 3 -veined. Lower glume apex acute. Upper glume elliptic; 20 mm long; 1.1 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma elliptic; 15–18 mm long; cartilaginous; without keel; 7 -veined. Lemma surface glabrous, or pubescent; hairy below. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; geniculate; triquetrous below; 15–25 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.