Spreading Dogbane (Apocynum androsaemifolium) vs. Hemp Dogbane (Apocynum cannabinum)
Updated June 19th, 2024These two species are visually similar and have a large range of overlap, although their habitats overlap little. They are easily distinguished by their blooms, or in winter by seed length, and they also have differences in growth habit. A. androsaemifolium prefers drier, shadier conditions, and acidic, sandy or rocky soil, whereas A. cannabinum is found in sunnier, wetter habitats that only become dry later in summer, with richer, loamy to clayey soil, or on calcareous rocks, and ranges farther south in the eastern and central portions of its range. These species can and do hybridize in much of their range, producing intermediate dogbane (Apocynum ×floribundum), which is uncommon and harder to identify.
