Broadly defined, this species is a variable hexaploid (2n = 48), widespread across eastern and central North America. Typical laeve is most common in midwestern regions, usually growing in more or less xeric grasslands and thin woodlands on base-rich soils. In Ky. there are records of apparent hybrids with undulatum and cordifolium (see colls. at EKY and B). Elsewhere hybrids are known with several other species in subsections Heterophylli, Dumosi and Porteriani (FNA 20).