Taxonomic update of the flax family in Mexico

Abstract

The taxonomy of the family Linaceae has not been updated for over two decades and, particularly in Mexico, there is no work evaluating the taxonomic status of all its species. This study provides an update and integrates each of the taxa in the family Linaceae distributed in Mexico. Specimens of plants of this family collected from across the distribution range in Mexico and deposited in herbaria and digital databases, as well as specialized literature, were reviewed. Twenty-four native and one introduced species belonging to two genera, in addition to two varieties, were recognized for the family; the rate of endemism is more than 50% and all native species are under some threat. Reflecting the previously limited knowledge of the group, many of the specimens that we studied had been misidentified. We provide morphological descriptions, supplemented with photographs, illustrations, morphological descriptions, synonymy, ecological data, assessment of conservation status, and a key to differentiate these species. Results presented here reduce the number of native Linum species present in Mexico, modify the distribution range of others, provide data about conservation, as well as new records, and support the presence of the genus Hesperolinon in Mexican territory.