Revista Mexicana de Biodiversidad 81: 27- 38, 2010 http://dx.doi.org/10.22201/ib.20078706e.2010.001.208 Tree and tree-like species of Mexico: gymnosperms, monocotyledons, and tree ferns Especies arbóreas y arborescentes de México: gimnospermas, monocotiledóneas y helechos arborescentes Martin Ricker* and Héctor M. Hernández Herbario Nacional de México, Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de México, Apartado postal 70- 233, Ciudad Universitaria, 04510 México D. F., Mexico. *Correspondent:
[email protected] Abstract. Trees or tree-like plants are defi ned here broadly as perennial, self-supporting plants with an adult height of at least 5 m (without ascending leaves or infl orescences), and with 1 or several erect stems with a diameter of at least 10 cm. We present an updated list of all Mexican tree species under that defi nition in the Gymnospermae (86 species, 38% endemic to Mexico), Monocotyledonae (75 species, 55% endemic), and Pteridophyta (9 species, none endemic). The list contains a total of 170 species in 37 genera and 12 families, with 74 species (44%) being endemic to Mexico. The list was compiled consulting recent literature, the National Herbarium of Mexico (MEXU), and taxonomic specialists. Key words: biodiversity, fl ora, tree defi nition. Resumen. Las plantas arbóreas o arborescentes se defi nen aquí en un sentido amplio como plantas perennes que se pueden sostener por sí solas, con una altura del adulto de al menos 5 m (sin considerar hojas o infl orescencias ascendentes), y con 1 o varios tallos erectos de un diámetro de al menos 10 cm.