Poa pratensis L. ssp. pratensis

Family: Poaceae, Tribe: Poeae

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

Poa agassizensis Bovin & D. Löve, P. angustifolia L.

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

Kentucky bluegrass

Primary Disseminule Type


Description (diagnostics are in brown)

Spikelets ovate to lanceolate, not bulbiferous, 3.5–6(7) mm long x 0.6–2 mm wide, laterally compressed, consisting of 2–5 fertile florets, with sterile florets at apex looking similar to fertile florets or reduced to a barren rachilla extension. Disarticulation at base of each fertile floret at maturity.

Glumes persistent, dissimilar, shorter than the adjacent lemmas, lanceolate, membranous, keels strongly compressed, scabrous. Lower glume 1.5–3 mm long, 1–3-veined. Upper glume 2–4 mm long, 3-veined.

Floret: rachilla persistent, <1 mm long (unless rachilla was barren, in which case it is usually longer and more slender), smooth, glabrous, callus woolly.

Lemma ovate to lanceolate, (2)3–4.3 mm long, membranous, keeled, 5(7)-veined, midvein distinctly ribbed, scabrous and ciliate, prominent lateral veins glabrous, marginal veins hairy, surface granulous, hairy at base, apex acute.

Palea 2–3 mm long, 0.9 length of lemma, keels scaberous, glabrous.

Caryopsis ovate to lanceolate, ca. 1.5–1.8 mm long x 0.5 mm wide, brown, embryo <0.33 length of caryopsis, hilum round.

Similar Species

Similar Species Comparison Chart

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)