PENDULOUS SPECIES OF USNEA FROM THE TEMPERATE FORESTS IN MEXICO

This study is the first step towards a modern, thorough treatment of t he genus Usnea in Mexico. Morphological, anatomical, and chemical feat ures as well as distribution of seventeen Mexican pendulous species co llected in temperate forests (1300 to 4000 m) are described. Usnea fir ma Mot, U. malmei Mot., U. scabrata Nyl. s. lat., and U. subscabrosa M otyka are new records for the country. Usnea goniodes (Stirt.) Motyka is new for the American continent. The following synonyms are proposed : Usnea ceratina Ach. (Syn. nov. U. solida Motyka), U. filipendula Sti rton (Syn. nov. U. sublaxa Motyka), U. himantodes (Syn. nov. U. serice a Motyka), U. malmei Motyka (Syn. nov. U. sorediata (Zahlbr.) Motyka), and U. mexicana Vainio (Syn. nov. U. duriuscula Motyka). Usnea sancta eritae Clerc & Herrera-Campos sp. nov, and U. vitrea Clerc & Herrera-C ampos sp. nov. are described. A key for Mexican pendulous species of U snea is provided.