A comparative study of Andreaea acutifolia, A. mutabilis, and A. rupestris

Abstract Andreaea rupestris, with a predominantly Northern Hemisphere distribution, is characterised by having ovate. rather blunt leaves and quadrate to shortly rhombic basal cells along the leaf margins. Much of what has been called A. rupestris in the Southern Hemisphere can be better referred to A. mutabilis, a dioicous species characterised by having narrow, lanceolate, acute leaves with subquadrate to rounded cells at the basal leaf margins. A. acutifolia, best distinguished by elongate basal cells at the margins and narrow, Ianceolate, acute to acuminate leaves, is widely distributed in the sub-antarctic-southern temperate zones and should be considered a species distinct from the former two species. Both A. rupestris and A. acutifolia are found at the higher elevations of the Hawaiian Islands, perhaps indicative of long-distance dispersal from both the Northern and Southern Hemisphere. A quantitative analysis of important characters confirms the distinctness of these three species. Typification of...