The sclerophyllous, evergreen vegetation found in Mexico under tropical climate is named "Mexical" (MEX) and presents many traits that have been thought to converge under a Mediterranean climate. Flowering phenology is strongly similar across Mediterranean-type ecosystems (MTEs) and this paper investigates MEX plant phenology in this context. The common history of the vegetation and the differences in the climatic conditions experienced by MEX and MTE taxi provide an ideal scenario to infer the relative importance of natural selection and historical constraints in the phenological response of plants to climatic conditions. This study has involved collecting field and bibliographic data on flowering phenology of MEX communities to detect (1) similarities at the community level between MTEs and MEX, (2) similarities between Tertiary and Quaternary taxi in MTEs and MEX, and (3) similarities between congeneric taxi from MEX and MTEs (taxi sharing a common ancestor but having evolved under different climates). Flowering in MEX does not occur mainly in spring, as in MTEs, but in summer, suggesting a response that maximizes water use in the rainy season. Flowering phenology of MEX species differed from their MTE congeneric species, suggesting that even though a common ancestor is shared, environmental pressures have led to different phenological responses in MEX and MTE plants. The flowering season for species that originated in the Tertiary and Quaternary did not differ in MEX, as expected, because of climatic uniformity along the whole time line. In MTEs, flowering differences between Tertiary and Quaternary species were not congruent, suggesting that the balance between the historical constraints and the selective farce of the Mediterranean climate is different among the three MTEs, and a particular explanation is needed for each.

Rosa María López helped in data collection. Michael G. Barbour provided valuable comments on the manuscript. Financial support was provided by DGAPA project IN 207798 to Alfonso Valiente-Banuet. MV was granted with a contract of the Reincorporación de Doctores y Tecnólogos del Ministerio de Educación y Ciencia during the preparation of the manuscript.

7 páginas, 1 figura, 2 tablas.

Peer reviewed