Origin and diversity of Mexican Convolvulaceae

Abstract

THE CONCULVACEAEREPRESENTED ONE OF THE LARGER AND MORE DIVERSE FAMILIES OF ANGIOSPERMS IN MEXICO, FIFTEEN GENERA AND ABOUT 217 SPECIES ARE KNOWN WITHIN THE POLITICAL BOUNDARIES OF THE COUNTRY. COMPARABLE DEGREES OF DIVERSITY IN BOTH PRIMITIVE AND ADVANCES GROUPS OF THE FAMILY ARE ENCOUNTERED IN OTHER TROPICAL REGIONS OF THE WORLD, SUCH AS SOUTH AMERICA, AFRICA, SOUTHEATS ASIA AND AUSTRALIA, SUGGESTING AND EVOLUTIONARY ORIGIN ANTEDATING THE BREAK-UP OF GONDWANALAND (CA. 100 MA). THE FAMILY EXHIBITS HIGH LEVELS OF ENDEMISM AT THE SPECIES AND SUBGENERIC LEVELS, THOUGH ONLY ONE GENUS IS ENDEMIC TO MEXICO AND GUATEMALA, ITZAEA, WHICH IS MONOTYPIC, SPECIES ENDEMISM IS HIGHEST FOR IPOMOEA IN TROPICAL ZONES, WHILE THE REMAINDER OF THE GENERA EXHIBIT HIGHER RATES OF SPECIES ENDEMISM IN ARID REGIONS. IN LIGHT OF RECENT ADVANCES IN THE TAXONOMY OF THE CONVOLVULACEAE, A REVISED CLASSIFICATION SCHEME FOR MEXICAN MORNING GLORIES IS PRESENTED, WITH DATA ON THE KNOWN DISTRIBUTION OF EACH SPECIES. A DISCUSSION ON THE REPRODUCTIVE BIOLOGY, MORPHOLOGICAL DIVERSITY AND ADAPTATIVE RADIATION WITHIN THE FAMILY IS PRESENTED.