Tangled Vines: Unravelling the Twisted Taxonomy of Banisteriopsis rusbyana

Ayahuasca brews are traditionally prepared with the leaves of Psychotria viridis or Diplopterys cabrerana, yet the latter has long been the subject of taxonomic confusion. Once thought to be synonymous with Banisteriopsis rusbyana, D. cabrerana has undergone decades of misidentification, conflation, and reclassification.

In this workshop, ethnobotanist Neil Logan traces the tangled taxonomic history of these sacred vines, presenting compelling new evidence that many plants previously labeled D. cabrerana in Peru and Ecuador are, in fact, a unique cultivar of Diplopterys longialata var. huambisa—a distinct lineage named in recognition of the Huambisa people and their ethnobotanical stewardship.

Through field-based observations, comparative morphology, and cultural context, Logan clarifies the identities, distributions, and ceremonial roles of these important admixture plants. This workshop is ideal for ethnobotanists, taxonomists, researchers, and practitioners interested in the evolving landscape of Amazonian plant taxonomy and the biocultural integrity of sacred medicine traditions.