The amazing number of ray flowers gives these flower heads either a delicate or a shaggy appearance, depending on how much they’ve been whipped about by the wind. The rays can be either white or, as here, pink. The flowers start to bloom in May; these were blooming in Squirrel Hill on about May 15.
Gray describes the genus and the species:
ERIGERON L. FLEABANE
Heads many-flowered, radiate, mostly flat or hemispherical; the narrow rays very numerous, pistillate. Involucral bracts narrow, equal, and little imbricated, never coriaceous, neither foliaceous nor green-tipped. Receptacle flat or convex, naked. Achenes flattened, usually pubescent and 2-nerved; pappus a single row of capillary bristles, with minuter ones intermixed, or with a distinct short outer pappus of little bristles or chaffy scales. Herbs, with entire or toothed and generally sessile leaves, and solitary or corymbed naked-pedunculate heads. Disk yellow; rays white, pink, or purple. (The ancient name presumably of a Senecio, from er, spring, and geron, an old man, suggested by the hoariness of some vernal species.)
E. philadelphicus L. Hairy; stem leafy, corymbed, bearing several small heads; leaves thin, with a broad midrib, oblong; the upper smoothish, clasping by a heart-shaped base, mostly entire ; the lowest spatulate, toothed; rays innumerable and very narrow, rose-purple or flesh-color. Throughout, locally common, generally in alluvial soil. May-Aug.