Have you ever wondered where a Puerto Rican plant grows, when it flowers, where it comes from? Here is an annotated checklist of the vascular plants presently found growing in the wild on the island of Puerto Rico that will be an invaluable aid to botanists, ecologists, foresters, and anyone else interested in the flora of Puerto Rico. The distribution of vascular plants within the island is provided according to a novel scheme that incorporates both broad physiographic areas and specific geographical sites, which are described in the text and illustrated by three maps. You will also find useful information on the times of flowering, fruiting, and spore production for each plant, along with references to recent monographs on Puerto Rican plants where fuller descriptions can be found.

In the past few years, there have been many changes in the names of individual plant taxa (species, subspecies, and varieties) and in the alignment of plant families. These changes are recorded in this work in such a way that older scientific names as well as Spanish common names can be tracked to new accepted ones. Since there is much overlap of the Puerto Rican flora with that of other Caribbean islands and regions, these nomenclatural changes will also be of use to researchers working in those areas.

This checklist covers 2,909 taxa that are included in 1,053 genera and 210 families. Of these taxa, 2,335 (80.2%) are native and 574 (19.7%) are exotic; of the native ones, 243 (10.4%) are endemic.