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Since the last century, the richness of the Canary Islands marine flora has attracted many botanists. Børgesen's seminal papers have been the main reference source for anyone interested in this flora. The first checklist of the marine macroalgae from the Canary Islands was published by Gil-Rodríguez and Afonso-Carrillo (1980a) with 434 macroalgal species being listed together with some dubious records. In recent years, the research efforts of local phycologists and the output of some scientific expeditions have yielded some new species and a large number of new records to the Canarian seaweed flora. The aim of this contribution is to compile an up-to-date catalogue of the marine plants for the Canary Islands (including cyanobacteria, macroalgae, seagrasses and fungi). The review of all published records of these marine plants takes into account the present taxonomic status and nomenclatural changes of the taxa concerned and rejects old and dubious records. After a careful review of the pertinent references and revision of live and preserved material, only valid records published before July 2001 are included in this checklist. Besides, each species is quoted for the islands in an east-west fashion to illustrate the distributional pattern of the species concerned. The marine flora of the Canary Islands is composed of 711 species, which are distributed as follows: 59 Cyanophycota, 385 Rhodophycota, 125 Chromophycota, 117 Chlorophycota, 3 seagrasses and 22 fungi. Compared to nearby regions, the Canarian archipelago comprises a much larger number of species. This high diversity appears to be the result of the combined effects of its geographic location, paleoclimatic events and the prevailing oceanographic conditions. [ABSTRACT FROM AUTHOR]

The biomass and production of the epiphytic community on the leaves of Cymodocea nodosa were measured during an annual cycle, from June 1991 to May 1992. The biomass of the epiphytes always increased with the age of the leaf in each shoot throughout the year. The mean annual biomass of epiphytes was 52.6 g dw m−² of leaf, with a maximum of 109 g dw m−² of leaf in November and a minimum of 33 g dw m−² of leaf in March. The biomass of the epiphytes was always lower than the biomass of the leaves on which they were growing, except in November. The epiphytic biomass varied from 124.1 g dw m−² meadow area in winter to 29.7 g dw m−² in spring. The mean annual contribution of the epiphytes to the total epigean biomass of the meadows was 31%, with the highest contribution of 34–57 % in autumn-winter and the lowest one of 17–28 % in spring-summer. The annual production of the epiphytes by shoot area was 453 mg dw year−¹ and the annual production of this epiphytic community per m² of meadow was 625 g dw year−¹. The mean production of the epiphytes was also estimated over the year. Two maxima were detected, one in winter of 90 μg dw cm−² day−¹, mainly due to the longest life-time of the leaves in these months (up to 90 days), and the other in late spring-early summer of 86 ×μg dw cm−² day−¹ because of the high contribution of seasonal epiphytes as well as the highest accumulation of biomass of epiphytes per day. In March and April, the minimum value of 38 μg dw cm−² day−¹ is directly related to the shortest life-time of the leaves in these months (up to 45 days). In general, the epiphytic flora on the leaves of the warm temperate seagrass Cymodocea nodosa showed biomass and productivity tendencies comparable to those known for other temperate and tropical seagrasses. [ABSTRACT FROM AUTHOR]