A New Species of Columnea (Gesneriaceae) from Ecuador with a Unique Correlation Between Leaf Symmetry and Stem Architecture

John L. Clark

doi:10.3417/20261089

John L. Clark Marie Selby Botanical Gardens https://orcid.org/0000-0002-1414-6380

DOI: https://doi.org/10.3417/20261089

Keywords: Anisophylly, Gesnerioideae, isophylly, Pastaza Valley, taxonomy

Abstract

Columnea dimorpha J. L. Clark (Gesneriaceae), a new species endemic to the Pastaza Valley of Ecuador, is described and illustrated. The species exhibits a distinctive vegetative dimorphism in which flexuous shoots consistently bear anisophyllous leaf pairs, whereas straight shoots consistently bear isophyllous leaf pairs. This correlated variation in stem architecture and leaf symmetry has not previously been documented in Columnea L. A conservation assessment based on the IUCN Red List Categories and Criteria supports a preliminary status of Vulnerable (VU).