Antipodal mosses: VIII. Valdonia gen. nov. (Seligeriaceae) from the Kerguelen Province in the Subantarctic

The taxonomic position of the Subantarctic species Blindia microcarpa Mitt. is discussed. It is reinstated as a distinct species, definitely different from B. contecta (Hook. f. & Wilson) Müll.Hal. from the antipodal islands of Campbell and Auckland in the cool temperate zone of the Australasian sector. B. microcarpa is considered to be a discordant element in the genus Blindia Bruch & Schimp. which differs from all other congeners by its very small capsules which are turbinate when dry and empty and hemispheric when wet; strongly modified, convolute-sheathing perichaetial leaves; straight or flexuose-secund leaves on drying; peristome teeth granulose on both ventral and dorsal surfaces; lack of prostome and stomata; heterogeneous costal elements; shortly rectangular to subquadrate laminai cells sheathing the long-excurrent costa; and longitudinal cuticular ridges on the leaf cells giving them a papillose appearance in cross-section. A new monotypic genus, Valdonia Ochyra, is established which is placed in the subfamily Dicranoweisioideae within the Seligeriaceae. The single species of the genus, V. microcarpa (Mitt.) Ochyra, endemic to the Kerguelen Province of the Subantarctic, is a constituent of fellfield vegetation and is particularly common on Prince Edward Island and Marion Island in the Prince Edward Islands archipelago. It appears to be less frequent on Îles Kerguelen from where it was actually described. The relationships of Valdonia are discussed and the details of the gametophytes and sporophytes of V. microcapa are illustrated.