Agrostis thurberiana

HABIT Perennial. Rhizomes short. Culms 15–30 cm long. Lateral branches lacking. Leaf-sheaths smooth. Ligule an eciliate membrane; 1–3 mm long; entire, or lacerate; truncate, or obtuse. Leaf-blades 0.5–3 mm wide.

INFLORESCENCE Inflorescence a panicle.

Panicle open; lanceolate; 5–10 cm long. Primary panicle branches ascending.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with a barren rhachilla extension. Spikelets elliptic; laterally compressed; 2–2.3 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent.

GLUMES Glumes persistent; similar; exceeding apex of florets; firmer than fertile lemma; shiny. Lower glume lanceolate; 2–2.3 mm long; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein scaberulous. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate; 2–2.3 mm long; membranous; 1-keeled; 1 -veined. Upper glume primary vein scaberulous. Upper glume lateral veins absent. Upper glume apex acute.

FLORETS Fertile lemma elliptic; 2 mm long; hyaline; without keel; 5 -veined. Lemma lateral veins excurrent. Lemma apex dentate; 4 -fid; truncate; muticous. Palea 1 length of lemma; hyaline. Rhachilla extension 0.1–0.3 mm long; pubescent.

FLOWER Lodicules 2; 0.5–0.6 mm long; membranous. Anthers 3; 0.4–0.6 mm long.

FRUIT Caryopsis with adherent pericarp. Hilum linear.

DISTRIBUTION North America: Subarctic, western Canada, northwest USA, and southwest USA.

NOTES Aveneae. Fl Pac NW 1994.

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