Morphologie et écologie de trois cytotypes de Minuartia hybrida (Vill.) Schischkin

Abstract

The populations of Minuartia hybrida from four places in the alluvial plain of the Ain river in the north-east of Lyon (France) have been studied from the point of view of ecology, morphology and cytology. Three microspecies have been detected: the first one with n = 35 (subsp. vaillantiana), the second one with n = 23 (subsp. hybrida) and the third one with n = 24 (belonging probably to M. hybrida Jordan). In three places, two races are sympatric. The almost unknown morphology of the cytotype with n = 24 has been stated. For subsp. vaillantiana it is the first record for the region of Ain-Rhône. The correlation between stamen number and chromosome number has been corroborated. Sterile plants with a bad pollen have been observed in two places. They are probably hybrids between two cytotypes.