Agrostis avenacea J. F. Gmel.

Family: Poaceae, Tribe: Aveneae

Pertinent Synonyms & Notes (particularly those used in California; go to GRIN for other synonyms)

Agrostis retrofracta Willd., Lachnagrostis filiformis (G. Forst.) Trin.

Pertinent Common Names (particularly those used in California; go to GRIN for other common names)

pacific bentgrass

Primary Disseminule Type


Description (diagnostics are in brown)

Spikelets solitary, pedicelled (1–5 mm long), typically consisting of 1 fertile floret, cuneate, laterally compressed, 2.5–3.5(4.2) mm long, disarticulating below the fertile floret.

Glumes persistent, similar, narrowly linear-lanceolate, exceeding apex of floret(s), membranous, shiny, gaping, keeled, 1-veined (primary veins scabrous, lateral veins absent), apices acuminate to acute. Lower glume 2.3 mm long, 0.9 length of upper glume. Upper glume 2.5 mm long, 1.4 length of adjacent lemma.

Floret: rachilla persistent, 0.3–1 mm long, tipped with a tuft of hairs to ca. 0.8 mm long, without significant palea, lanceolate, callus blunt, oblique, glabrous or ringed by minute hairs 0.3–0.4 mm long. Lemma lanceolate, 1.3–2(2.3) mm long, hyaline, without keel, 5-veined, surface pubescent, apex truncate, dentate, 4-fid (lateral veins very shortly excurrent), awn arising from 0.75 way up back of lemma, 3–7.5 mm long, geniculate, with twisted column.

Palea 0.5–0.8 length of lemma, hyaline, 2-veined (keels ca. 0.1 mm apart), apex obtuse.

Caryopsis elliptic to lanceolate, 0.8–1.3 mm long x 0.3–0.5 mm wide, dark brown, embryo <0.25 length of caryopsis, hilum linear.

Similar Species

Agrostis stolonifera

Risk Assessment (codes in yellow or red indicate cause for concern; assessments are current as of mid-2011; click AUQP, NZBORIC, or NZBPI for access to the most recent versions of these databases and possible assessment changes)