Poa trivialis is a perennial C3 grass (Waller and Lewis 1979), to 1 m tall, stems tufted, prostrate at base (kneeling) sometimes with short stolons; sheaths rough, ligule to 0.7 cm long, longer than wide, membranous.
Leaves alternate, blade soft, long, 0.2-0.6 cm wide, tip boat-shaped.
Flower spikelets 0.3-0.4 cm long, flattened, numerous, crowded, 2-3 flowered, glumes narrow, curved inward first ca 0.2 cm, second ca 0.2-0.3 cm, lemmas narrowly egg-shaped, webbed at base, hairy along keeled mid-vein, otherwise hairless; inflorescence open, branches rough, in sets of 5-8 about main axis.
Wetland status: FACW.
Frequency in NYC: Infrequent in natural areas.
Habitat: Moist fields, roadsides, meadows, soil pH 4.8-7.5, tolerant of fire, shade, intolerant of drought, salt (USDA, NRCS 2010).