Agrostis rossiae

HABIT Annual; caespitose. Culms 9–15 cm long. Lateral branches lacking. Leaves mostly basal. Leaf-sheaths loose. Ligule an eciliate membrane; 1–2 mm long; erose. Leaf-blades flat, or conduplicate; 1–2.5 cm long; 1–2 mm wide. Leaf-blade surface scabrous; rough adaxially.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 5–6 cm long; with spikelets clustered towards branch tips. Primary panicle branches ascending; whorled at most nodes.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets elliptic; laterally compressed; 2–2.5 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; 2–2.5 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; 2–2.5 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; 1.5 mm long; hyaline; without keel; 5 -veined. Lemma lateral veins extending close to apex. Lemma apex dentate; 4 -fid; truncate; muticous. Palea 0.6 mm long; 0.4–0.5 length of lemma; hyaline.

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

FRUIT Caryopsis with adherent pericarp. Hilum linear.

DISTRIBUTION North America: northwest USA.

NOTES Aveneae. Fl Pac NW 1994.

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