S Angeles Cárdenas

Phytogeography of High-Elevation Mosses from Chiapas, Mexico

The highlands of Chiapas, Mexico, harbor temperate moss taxa which are common at similar or higher elevations in central and southern Mexico. The tropical taxa are confined, for the most part, to lowland moist sites, but in Chiapas several of them reach elevations beyond 2,700 m. This moss flora includes 155 taxa which may be divided into five phytogeographical elements; the most important in terms of number of species are the Meso-American and the Wide distribution elements. Aptychella and Grimmia are new to Chiapas and Daltonia lindigiana Hampe, D. te- nuifolia Mitt., and Orthotrichum trachymitrium Mitt. are new to Mexico.

Observations on Moss Succession on Paricutín Volcano, Mexico@@@Observations on Moss Succession on Paricutin Volcano, Mexico

Thirteen moss species were found on lava flows on Paricutin Volcano and 34 in the surrounding forest near Angahudn. The latter is within the area of partial destruction by cinder. Through fifty years ofprimary succession, the number of moss species has not increased substantially, but they seem to occupy all major microhabitats on the lava flows; mosses observed on soil in the forested area had ample opportunity for reoccupation, while the epiphytic taxa may have survived in protected microhabitats.

Lorentziella imbricata and Oreoweisia delgadilloi in Mexico

Lorentziella imbricata (Mitt.) Broth., currently known from the United States (Texas) and South America, is reportedfrom Mexico for thefirst time. The known distribution of Oreoweisia delgadilloi Robins. & Bowers is extended to central Mexico.