Seed morphology in Moehringia L. and its taxonomic significance in comparative studies within the Caryophyllaceae

Seeds of 30 species of Moehringia and 12 representatives of the Caryophyllaceae were examined with the Scanning Electron Microscope. High diversity was found in seed coat micromorphology, and a number of novel morphological features have been observed. Comparison with other representatives of the Caryophyllaceae has provided new insight into the potential taxonomic value of discrete morphological characters. Though many characters appear informative within Moehringia, they are affected by a high level of homoplasy when considered in a wider phylogenetic context. Smooth seed is the common condition in Moehringia, except for Eastern Balkan and Iberian species that maintain a secondary ornamentation of the testa cells resembling the plesiomorphic Caryophyllaceaetype. Five types of strophioles were recognized, in accordance with previous literature. Among these, the strophiole of the Iberian species appears very distinctive and a proper strophiole could not be verified in M. glochidisperma and M. fontqueri.