Helictotrichon desertorum

HABIT Perennial. Basal innovations intravaginal. Culms slender; 30–60 cm long. Leaf-sheaths glabrous on surface, or puberulous. Ligule an eciliate membrane; 3–8 mm long; acute. Leaf-blades filiform; 20–50 cm long; 0.5–0.7 mm wide; grey-green. Leaf-blade surface ribbed.

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

Panicle open; linear, or oblong; 5–8 cm long. Primary panicle branches bearing 2–3 fertile spikelets on each lower branch.

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; 9–12 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 2–2.5 mm long; pilose; with 2.5–3 mm long hairs. Floret callus pilose. Floret callus hairs 2 mm long.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma. Lower glume elliptic; 6.5–9 mm long; 0.66–0.8 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume elliptic; 10–11 mm long; 1.1–1.2 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma elliptic; 8–10 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; 12–17 mm long overall; with twisted column. Palea 8–9 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: central and eastern. Asia-temperate: Siberia, Soviet Middle Asia, China, and Mongolia.

NOTES Aveneae. Fl Eur 1995.

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