Introduction
The botanical survey of the Canary Islands by Webb and Berthelot in the 19th century provides a detailed account of the diversity of mosses (bryophytes) present in the archipelago. The authors aimed to offer a historical overview of cryptogamic discoveries in the islands and to establish relationships between the primitive Canarian vegetation and that of neighboring continents[1].
Richness and Distribution of Canarian Mosses
Webb and Berthelot documented 76 species of mosses in the Canary Islands, of which only three were new to science at the time. This figure, according to the authors, exceeded expectations based on the belief that the proportion of acotyledonous plants decreases towards the equator, a view they themselves question[1].
The distribution of these species was not uniform among the islands. Eight species were found on all islands, 37 on Gran Canaria, 26 on Tenerife, three on La Gomera, and two on El Hierro. Notably, according to Webb and Berthelot, all new species originated from Tenerife, specifically from the Agua-García forest, except for Glyphocarpus Webbiü, found at the summit of the Orotava valley[1].
Ecological Preferences and Habitats
The authors detail the preferred habitats of Canarian mosses: 24 species were found on tree trunks or at their base, 29 on the ground, two on walls, four in peat bogs, seven on rocks or in their crevices, six in shady and humid places, and three in the densest forests[1].
Geographic Affinities
According to Webb and Berthelot, the moss flora of the Canary Islands shows a marked analogy with that of southern and western Europe, especially with major Mediterranean islands such as Corsica and Sardinia. There are also links with the flora of northern and western Africa, as well as the coasts of Portugal, France, and England. However, most species belong to the European flora, particularly Mediterranean regions[1].
Classification and Proportions
Regarding classification, Canarian mosses are distributed among twelve tribes, with Hypneæ being the most numerous with 30 species. Acrocarpous mosses greatly outnumber pleurocarpous mosses, in a ratio of 13 to 5, which matches observations in other European floras[1]. Among pleurocarps, Hypnes predominate. Of the 76 species, 38 are diploperistomate, 32 haploperistomate, and three aperistomate.
Authors’ Final Considerations
Webb and Berthelot emphasize that, although the number of species collected was high for their time, they believed that an experienced cryptogamist could easily double or triple the number with a longer stay on the islands, given the variety of habitats and the richness of the forests[1].