Pollen and morphometric analysis reveal Solanum tavinuuyuku (Solanaceae), a new dioecious species from Mesoamerican Solanum sect. Anarrhichomenum

Solanum tavinuuyuku, of the Sierra Madre del Sur ecoregion of South-Central Mexico, is a viny, node-rooting species of the Potato clade, in the subclade Solanum sect. Anarrhichomenum. Solanum tavinuuyuku is distinguished from its relatives by possessing long and narrow, lanceolate, ovate to falcate, 1–3 - foliate leaves with (5 –) 7–10 secondary veins; large, persistent pseudo-stipules found at nearly every node on herbarium material; and white, violet-tinged corollas particularly pronounced in the floral bud.

Solanum tavinuuyuku is functionally dioecious, producing functional, tricolporate pollen and non-functional, inaperturate pollen in short and long-styled flowers, respectively, joining its close relative S. appendiculatum as one of only two documented dioecious species in the entire Potato clade. Separation of S. tavinuuyuku from its closest ally, the simple-leaved S. ionidium, is based on morphometric and geographic evidence presented here.