VARIABILIDAD MORFOLÓGICA DE RUPRECHTIA APETALA WEDD. (POLYGONACEAE) EN LAS SIERRAS PAMPEANAS Y SUBANDINAS DE LA ARGENTINA.

Background and aims: Ruprechtia apetala (Polygonaceae) is a woody Chaquenian species with large morphological variability throughout its distribution range. The present study attempts to evaluate this variability within Argentina. M&M: Forty-two individuals were collected from six Argentinian provinces, corresponding to the regions of Sierra Chaco, Piedmont Forest and the transition zone between them. Numerous morphological characters, both reproductive and vegetative, were analyzed. Principal Components and Conglomerates Analysis were performed, in order to establish the existence of morphogroups; the latter were evaluated by univariate analysis (Kruskal-Wallis test and cluster description by R) and multivariate (ANOSIM and PERMANOVA), to detect possible significant intraspecific differences. Additionally, a distribution map of the collected specimens was drawn up. Results: From the multivariate analysis two morphological groups were detected, mainly at foliar and growth habit levels. The ANOSIM and PERMANOVA analysis show a significant global difference among both groups (p-value < 0,05); however, the corresponding statistics indicate a high similarity between them. Additionally, it was demonstrated that no characters are mutually exclusive to either group. Conclusions: Observed morphological differences between specimens from different biogeographical regions, though not mutually exclusive, allow postulating the existence of ecotypes within the species. [ABSTRACT FROM AUTHOR]