Prenanthes alba is recognized by the purplish stems, relatively large, coarse, ovate or triangular leaves, relatively long, winged petioles, glabrous and often purple phyllaries, and usually reddish brown pappi. The leaves are variable, occasionally deeply 3-lobed. W. L. Milstead (1964) recognized specimens with a pale yellow pappi as “subsp. pallida,” distributed on the east coast in New Jersey, Virginia, and North Carolina. Because pappus color tends to fade somewhat on herbarium specimens, that character is difficult to assess on older specimens. The name was not validly published.