Agrostis howellii

HABIT Perennial; caespitose. Culms 30–60 cm long. Lateral branches lacking. Leaf-sheaths scaberulous. Ligule an eciliate membrane; 2–3.5 mm long; erose, or lacerate; obtuse, or acute. Leaf-blades 15–25 cm long; 3–5 mm wide; flaccid.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; effuse; 10–20 cm long; with spikelets clustered towards branch tips. Primary panicle branches spreading.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets elliptic; laterally compressed; 3.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent. Floret callus hairs 0.5 mm long.

GLUMES Glumes persistent; similar; exceeding apex of florets; firmer than fertile lemma; shiny. Lower glume lanceolate; 3.5 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 acuminate. Upper glume lanceolate; 3.5 mm long; membranous; 1-keeled; 1 -veined. Upper glume primary vein scaberulous. Upper glume lateral veins absent. Upper glume apex acuminate.

FLORETS Fertile lemma elliptic; 2.5 mm long; hyaline; without keel; 5 -veined. Lemma lateral veins extending close to apex. Lemma apex dentate; 4 -fid; truncate; awned; 1 -awned. Principal lemma awn dorsal; arising 0.1–0.2 way up back of lemma; geniculate; 6–7 mm long overall; with twisted column. Palea absent or minute.

FLOWER Lodicules 2; 0.4 mm long; membranous. Anthers 3; 1–2 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.