Abstract
A new microspecies of the Portulaca olearacea aggregate was identified in the course of a seed coat morphology analysis of 385 specimens from 55 sites located in Sardinia. This new taxon is here described under the name Portulaca sardoa. Apart from seed coat ornamentation, the new species differs from the others in chromosome number (2n = 48). Furthermore, a simplified key for the identification of the microspecies is provided.
Acknowledgments
We thank Dr. T. Raus, Dr. P.H. Raven, and Dr. N. Kilian for their assistance during the study. Thanks are due to Mr. M. Dvorachek, The Geological Institute in Jerusalem for preparing most of the scanning electron micrographs and to Dr. Giovanna Becca, Department of Science for Nature and Enviromental Resources, University of Sassari, for the technical support provided for caryological analyses. We thank Ms. Monika Lüchow, the Botanical Garden and Museum, Berlin – Dahlem, for making the sketch of the chromosome plate.