Scientific Name
Poa pratensis L.
Common Name(s)
Kentucky bluegrass
Tribe / Family Name
Poeae
Flowering Period
May to September
Symbol
POPR
Description
Kentucky bluegrass is an introduced cool-season rhizomatous perennial grass; reproduction occurs from seeds, tillers, and rhizomes. Culms usually range from 5–70 cm in height. Its inflorescence is a loosely contracted to open panicle usually 2–15 cm long and often pyramidal with lower branches in whorls of 3–5. Spikelets are usually 3.5–6 mm long, ovate, laterally compressed, green or purplish, 2- to 5-flowered, and unawned. Lemmas are lanceolate, green or purple-tinged, and webbed at the base. Ligules are usually up to 2 mm long, membranous, truncate, usually entire, ciliolate, and pubescent adaxially.
General Info
Kentucky bluegrass can be found in areas with abundant soil moisture, meadows, open woodlands, foothills, plains, disturbed sites, such as roadsides and open ground, and montane to subalpine sites.
Similar Species
Kentucky bluegrass may look similar to other bluegrass (Poa) species, with keeled (boat-shaped) leaf tips, panicle seed heads, and florets without awns. To distinguish it from other bluegrasses, remember to look for its distinctive long and often upright leaf blades, loosely contracted to mostly open panicle inflorescence, and lemmas that are webbed at the base. Also, it usually grows on wetter sites than most other bluegrasses. There are many subspecies and varieties of Kentucky bluegrass.
Picture of growth habit.
Inflorescence is a loosely contracted to open panicle.
Close-up picture of spikelet.
Close-up picture of lemma. Note the webbed base and silky pubescent nerves.
Close-up picture of membranous ligule.
Illustration of Kentucky bluegrass. USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913. <i>An illustrated flora of the northern United States, Canada and the British Possessions. 3 vols</i>. Charles Scribner's Sons, New York. Vol. 1: 256.
Distribution map of Kentucky bluegrass. USDA PLANTS Database, 2022.