BRAY JR., JAMES R. Department of Plant Biology, Southern Illinois University, Carbondale, IL 62901-6509. - The genus Fossombronia Raddi in North America, north of Mexico.
Fifteen taxa have been listed for the genus Fossombronia Raddi
in North America, north of Mexico. The difficulty in delimiting
species based on gametophyte morphology has led the majority of
bryologists to identify species of Fossombronia using
characters of the distal spore wall architecture. Attempts to compare
these data with other morphological and ecological data are lacking,
leading to a total misunderstanding of the species within this genus.
Also, many reports were based on previous literature rather than on a
thorough evaluation of type material. As part of a complete revision
of the genus for Europe and North America, north of Mexico, a
character set generated from light and SEM analysis of type
collections, supplemented with other collections and live material,
was compared in a phylogenetic framework and used to generate parallel
descriptions of all accepted taxa. Common garden experiments were
conducted to assess morphological plasticity of the gametophyte and
spore wall characters through successive generations. Based on
specimen evaluation, common garden results and taxonomic reduction, a
total of ten species are here recognized for North America, north of
Mexico.
Key words: common garden, Fossombronia, morphology, North America, revision