This is widespread in eastern and central North America. Chromosome number varies (2n = 18, 36, 54), generally increasing from east to west, but it may not be clearly associated with morphological segregates (FNA 20). Although much less abundant in Ky. than altissima, gigantea occurs along larger streams and in lowland meadows across most the state. S. gigantea is distinguished from the canadensis-altissima complex in Ky. by its completely glabrous stems below the inflorescence (versus puberulent at least above middle), often with glaucus bloom at first then turning purplish (versus just yellowish-green). Leaves are generally glabrous, except (at least in var. gigantea) for hairs along the three main veins on lower sufaces (versus usually pubescent across the surface). Flowers are similar, but tend to appear a month or so earlier, mostly in August (versus September).