Key to Wisconsin Apocynaceae

Author: John G. Zaborsky

• 1a.Plant a trailing evergreen creeper; flowers solitary in the leaf axils; corolla blue; seeds glabrous Vinca

• 1b.Plant herbaceous, not evergreen, erect or a twining vine; flowers in terminal or axillary umbels or cymes; corolla color various, but never blue; seeds with a tuft of soft hairs 2

• 2a.Vines with twining stems Vincetoxicum

• 2b.Erect or ascending herbs, not twining 3

• 3a.Corolla lobes reflexed at maturity; flowers in umbels; filaments fused into a column with elaborate appendages; anthers fused into a head around, and fused to, the pistils Asclepias

• 3b.Corolla lobes erect to spreading; flowers in cymes; filaments unfused; anthers unfused (but lying against the pistils) Apocynum