Genus Trichomanes L. (Linnaeus 1753)

As evidenced by Bauret et al. (2015), several paleotropical species formerly attributed to Trichomanes (the genus is mostly neotropical) are morphologically close to Abrodictyum spp. However, the single Comorian species T. boivinii Bosch is clearly distinct from Abrodictyum pseudorigidum occurring in the archipelago (see Fig. 4). The rhizomes of T. boivinii are short-creeping while those of Abrodictyum pseudorigidum are mostly suberect to erect. The main differences concern the ultimate segment shape. In T. boivinii, ultimate segments are multi-veined, ovate, spatulate and more or less toothed. In Abrodictyum pseudorigidum, ultimate segments are uni-veined, linear, and entire with tapered ends. Compared to Tardieu-Blot (1951) and Roux (2009), T. boivinii is new for the archipelago, although the species had already been reported by Kuhn (1868).