New data about the extinct liverwort Porella pinnata L. (Porellaceae, Jungermanniales, Hepaticae) in Portugal. C. Garcia 1 , C. Vieira 2 , C. Sérgio 1 1 Universidade de Lisboa. Museu Nacional de História Natural. Jardim Botânico/Centro de Ecologia e Biologia Vegetal da Faculdade de Ciências da Universidade de Lisboa. Rua da Escola Politécnica, 58. 1250-102 Lisboa, Portugal. cgarcia@fc.ul.pt 2 Universidade do Porto, Departamento de Botânica da Faculdade de Ciências & Centro de Investigação em Biodiversidade e Recursos Genéticos (CIBIO). Rua do Campo Alegre 1191. 4150-181 Porto. ccvieira@fc.up.pt Abstract: Porella pinnata L. was considered an extinct species in the Portuguese Red List of Bryophytes, but during recent field work and after revising some old material of the PO Herbarium, new populations of Porella pinnata L. were discovered in different regions of North of Portugal. These populations correspond to the first reports in more of 80 years, after the ancient gatherings made by Alphonse Luisier and António Machado in the beginning of the twentieth century. Key Words: Porella pinnata, threatened species, freshwater disturbances, Portugal. INTRODUCTION Porella pinnata L. has been considered an Extinct (Ex) species in Portugal, since this liverwort has not been collected for more than eighty years (Sérgio et al., 1994, Sérgio et al., 2001). In Portugal, this species was first reported by Luisier (1910), in Minho Region (classic locality: river Selho, Guimarães, found in 1907 and 1908). Another reference for this species was reported, in the same region, by Machado (1925) after the collection of the species in Coura river, Formariz.