Linear and geometric morphometrics as tools to resolve species circumscription in the Pseudolaelia vellozicola complex (Orchidaceae, Laeliinae)

Abstract

Background and aims - Pseudolaelia is a genus endemic to eastern Brazil, with 12 accepted species predominantly distributed across granitic inselbergs of the Brazilian Atlantic Forest. The aim of the present study was to distinguish between the very similar taxa P. aguadocensis, P. oliveirana, P. regentii and P. vellozicola, using morphometric data acquired as linear measurements and outlines capture with Elliptic Fourier Analysis (EFA) of the floral parts. Material and methods - We sampled 208 specimens from 11 natural populations of the above taxa. We measured 20 floral variables and for the EFA, and we extracted 24 shape variables from the Fourier coefficient matrices, which describe the outlines of the floral parts. In both cases the data were analyzed with multivariate methods (both ordination and clustering). Key results - We could not find morphological discontinuities with sufficient magnitude to consider P. aguadocensis, P. oliveirana and P. regentii as distinct species from P. vellozicola. Conclusions - We propose that P. vellozicola should be considered a polymorphic and widely distributed species, generally supported by both methods.