The distribution and status of species of Vincetoxicum in eastern North America

SHEELEY, S. C. AND D. J. RAYNAL (College of Environmental Science and Forestry, State University of New York, Syracuse, NY 13210). The distribution and status of Vincetoxicum nigrum (L.) Moench, V. rossicum (Kleo.) Barb. and V. hirundinaria Medik. in eastern North America Bull. Torrey Bot. Club 123:148-156. 1996.Vincetoxicum nigrum (L.) Pers., (Kleo.) Barb., V. rossicum and V. hirundinaria Medik. (Asclepiadaceae) are exotic twining perennial herbs found in eastern North America. The nomenclatural status as well as the historical and current distribution of these plants were surveyed by studying floristic manuals of flora and journal literature and by examining herbarium specimens, and corresponding with authorities familiar with the species. Vincetoxicum rossicum is the most invasive of the species, often forming large colonies; it occurs from the northeastern Atlantic coast W to S Michigan and from S. Ontario to s. Pennsylvania. Vincetoxicum nigrum and V. hirduninaria appear less aggressive and have more limited patterns of distribution. Vincetoxicum nigrum occurs from the northeastern Atlantic Coast west to Missouri and Kansas and from southern Ontario to southern Pennsylvania. Vincetoxicum hirundinaria is found in southern Ontario, New York and Pennsylvania. Vincetoxicum species may persist for decades after establishment, spreading vegetatively and by means of polyembronic seeds.