The genus Rumohra Raddi (Pteridophyta, Dryopteridaceae) in Madagascar: a new species and two new combinations

The genus Rumohra Raddi (Pteridophyta, Dryopteridaceae) in Madagascar: a new species and two new combinations. Four of the five species of Rumohra known in the world live in Madagascar. Three of them are endemic to the island. This new treatment since that of Tardieu-Blot (1958) establishes the synonymy between R. capuronii Tardieu and R. adiantiformis (G.Forst.) Ching, and between R. glandulosa Tardieu and R. lokohensis Tardieu. It also gives a description of a new species, R. linearisquamosa Rakotondr. This species differs from all others by the morphology of the scales. Those of the rhizome are linear with an irregularly dentate margin, those of the abaxial side of costae and costulae are substellate or arachnoid. A new key for the identification of the species supplements the taxonomic information. The description, distribution map on the island and list of herbarium samples available in Paris are given for each species.