The Origin of Trimeris (Lobeliaceae) Is Illuminated by a Second Species, T. anceps

Abstract

A new combination, Trimeris anceps (L. f.) E. B. Knox, is established for the species previously known as Lobelia anceps L. f. Lobelia L. is the “core” genus of the Lobeliaceae, which has more than 30 segregate genera that have been recognized based on their evolutionarily divergent reproductive morphology. Wimmerella Serra, M. B. Crespo & Lammers is a segregate South African genus with completely fused corollas (which affect pollinator access), yet one of its descendant lineages has somehow reverted to the Lobelia-like condition of the corolla split to the base on the back. Recent discovery that the St. Helena–endemic T. scaevolifolia (Roxb.) Mabb. is sister to L. anceps provides an established segregate genus into which both of these morphologically anomalous species can be placed.