Symphyotrichum lateriflorum is a perennial herb 30-120 cm tall, from a root crown. Stems sparsely to densely hairy, often purple-tinged, branched from middle or below middle.
Leaves alternate, basal leaves stalked, elliptic or widest above middle, to 8cm long, 4 cm wide, margin toothed or entire, sometimes persistent; stem leaves soon deciduous, stalkless (sessile), lance-shaped to linear, 5-15 cm wide, 0.5-3 cm wide, pointed at both ends, leaves of branches sharply reduced.
Flowers: ray flowers white, 9-15, about 0.5 cm long, disk flowers yellow, becoming purplish, (0.3-0.5 cm long, lobes 0.1-0.15 cm, curved back); flower heads goblet shaped, basal (involucre) bracts 3-4 rows, midrib broadly green or purplish, blooming Aug.-Oct.
Fruit dry, 1-seeded, achene, with tuft of hairs (pappus), equal to or shorter than disk flower.
Wetland status: FACW-.
Frequency in NYC: Infrequent.
Habitat: Open wet to moist soil of meadows and edges.
Notes: Host to larvae of the pearly crescent butterfly, Phycoides tharos (Nymphalidae), (Tallamy 2003; Pyle 1981).