Erigeron philadelphicus is a biennial to short-lived perennial herb, 20-80 cm tall, stems hairy, soft, branched only in inflorescence; from fleshy, fibrous roots, appears to sprout from root crown occasionally (Gargiullo personal observation).
Leaves alternate, those of basal rosette and lower stem narrow, 1.5–15 cm long, 1–4 cm wide (Flora of North America 1993+), smaller upwards, margins shallowly blunt-toothed to pinnately lobed, widest above middle, hairy, tip rounded, stem leaves sessile to clasping, blunt-lobed at base, margin coarsely toothed to shallowly lobed especially above middle, hairy on both sides; leaves of basal rosette and lower stem dying as inflorescence develops.
Flowers in radiate heads, rays pink-white, 150-400, linear, 0.5-1.0 cm long, 0.05 cm wide, disk flowers yellow, 0.2-0.3 cm long, disk 0.6-1.5 cm wide, basal bracts of floral head hairy 0.4-0.6 cm long; blooms and fruits March-Sept.; pollinated by insects.
Fruit dry, 1-seeded achene, ca 0.1 cm long, 2-ridged, with a plume of 20-30 bristles (Flora of North America 1993+) ; seeds wind dispersed.
Wetland status FACU.
Frequency in NYC: Infrequent.
Habitat: Open areas, roadsides, meadows, fill. Soil pH 4.8-7.8, tolerant of partial shade (USDA, NRCS 2006).
Notes: An early successional plant probably requiring open soil (Keever 1979). Seed germination in late summer to early autumn, overwintering as rosettes (Kenny 1996; Keever 1979).