Morphological Variation in Quinchamalium (Schoepfiaceae) is Associated with Climatic Patterns along Its Andean Distribution

Abstract

Quinchamalium (Schoepfiaceae) is a root hemiparasite with a broad geographic range throughout the Andes. Regional studies have used various vegetative and floral traits to describe and identify species, but there has been no detailed analysis of the continuum of morphological variation across the entire geographic range of this genus. Currently 21 species names are being used in the genus but their taxonomic distinctiveness is unclear. The aim of this study was to use multivariate analyses to identify patterns of morphological variation, assess the existence of morpho-species, and correlate variation with climatic and geographic factors. Two putative species were initially circumscribed based on corolla length, and this hypothesis was tested using principal component and discriminant analyses of 17 vegetative and floral characters obtained from 117 herbarium specimens. No statistically significant support was obtained through multivariate analyses for the existence of the two morpho-species, thus, only one species is recognized, a widespread and variable Q. chilense. Patterns of co-variation between several morphological traits and climate were identified. Taller plants with larger flowers were associated with sites with higher precipitation, and narrower leaves with higher temperatures. The presence of thrum flowers (floral morphs with relatively short styles) was correlated with higher latitudes and lower temperatures. Nevertheless, we have not determined whether these variations are genetically fixed ecotypes or are a consequence of phenotypic plasticity.