Helictotrichon hookeri

HABIT Perennial; caespitose. Culms erect; 30–40 cm long. Leaf-sheaths glabrous on surface. Ligule an eciliate membrane; 1–3 mm long; lacerate. Leaf-blades flat, or conduplicate; 2–4 mm wide. Leaf-blade surface scaberulous; glabrous. Leaf-blade margins cartilaginous.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; linear, or lanceolate; 5–10 cm long. Primary panicle branches appressed; bearing 1–2 fertile spikelets on each lower branch.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 4–6 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 15 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes pilose. Floret callus pubescent.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma. Lower glume elliptic; 12 mm long; 0.8–0.9 length of upper glume; membranous; 1-keeled; 3 -veined. Lower glume apex acute. Upper glume elliptic; 14 mm long; 1–1.4 length of adjacent fertile lemma; membranous; 1-keeled; 5 -veined. Upper glume apex acute.

FLORETS Fertile lemma elliptic; 10–13 mm long; cartilaginous; without keel; 5–7 -veined. Lemma surface scaberulous. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; geniculate; 10–15 mm long overall; with twisted column.

FLOWER Lodicules 2; 2 mm long. Anthers 3; 4–5 mm long. Ovary pubescent on apex.

FRUIT Caryopsis with adherent pericarp; hairy at apex. Hilum linear.

DISTRIBUTION Europe: eastern. Asia-temperate: Siberia, Soviet far east, Soviet Middle Asia, China, and Mongolia. North America: Subarctic, western Canada, eastern Canada, northwest USA, north-central USA, and south-central USA.

NOTES Aveneae. Fl Pac NW 1994.

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