Family Compositae or Asteraceae.
No photograph can convey the vivid purple color of ironweed, one of our most spectacular late-summer flowers. A field of mixed ironweed and goldenrod is a sight not easily forgotten. Two species are common in our area, and they hybridize; Tall Ironweed is, as its name implies, taller than New York Ironweed (Vernonia noveboracensis), but otherwise very similar. See Gray’s description below for other differences to note. These were blooming in Beechview in early September.
Gray describes the genus and the species, which he lists as V. altissima:
VERNÒNIA Schreb. IRONWEED. Heads discoid, 16 many-flowered, in corymbose cymes; flowers perfect; involucre shorter than the flower , of much imbricated bracts. Achenes cylindrical, ribbed; pappus double, the outer of minute scale-like bristles, the inner of copious capillary bristles.—Perennial herbs, with leafy stems, alternate acuminate or very acute serrate leaves and mostly purple (rarely white) flowers. (Named for William Vernon, an early English botanist, who traveled in North America.)
Involucral bracts obtuse, acute, or acuminate, but not conspicuously caudate.
Lower surface of the leaves smooth or merely puberulent.
Cyme open and loose, the branches wide-spreading.
V. altissima Nutt. Usually tall (1-2 or more m. high); leaves lance-oblong, acuminate, spreading, smooth or merely puberulent beneath; cyme large, widely spreading, rather loose; heads about 25-flowered; involucral bracts closely appressed, ovate, acute, obtuse, or cuspidate, mostly purple-tinged; flowers red-purple. (V. maxima Small.)—Rich soil of prairies, etc., N. Y. to Mich., Mo., and southw.; also sporadic northeastw.