The red algal genus Liagora (Liagoraceae, Rhodophyta) from the Canary Islands

Eight species of the genus Liagora (Liagoraceae, Rhodophyta) are reported from the Canary Islands. Six of these (L. viscida (Forsskal) C. Agardh, L. distenta (Mertens) Lamouroux, L. gymnarthron Borgesen, L. canariensis Borgesen, L. maderensis Kiitzing and L. tetrasporifera Borgesen) are endemic to the NE Atlantic and Mediterranean and two (L. valida Harvey and L. ceranoides Lamouroux) have a wide distribution. L. maderensis, known only from the type collection and often cited as a synonym for L. ceranoides or L. valida, has a reproductive and vegetative morphology that supports its recognition as an independent species. Evidence suggests that L. gymnarthron has often been erroneously identified as L. distenta (Mertens) Lamouroux and that the latter species has thus been characterized by a combination of features from two different taxonomic entities. Although closely related, the two species show distinctive differences in the morphology of their cystocarps: in L. distenta sterile filaments persist under the gonimoblast and do not surround the mature carposporophyte, while in L. gymnarthron mature carposporophytes are surrounded by a conspicuous involuc�e. Habit, vegetative and reproductive development have been examined in the eight species. The previously controversial reproductive development in L. viscida, the lectotype species of the genus, has been clarified. Gametophytes of L. viscida are monoecious and, after presumed fertilization, cells adjacent to the supporting cell form sterile colourless filaments that grow and branch towards the thallus surface; simultaneously gonimoblast initials produce outwardly radiating lax gonimoblast filaments that form terminal carposporangia, resulting in a mature carposporophyte with sterile filaments intermingled with the gonimoblast filaments. The features used at present to delineate the genus Liagora in the Liagoraceae are analysed and the potential use of postfertilization characters to subdivide the genus is discussed

Morfología y distribución de Ganonema farinosa (Rhodophyta, Liagoraceae) en las Islas Canarias

Se estudia el hábito y el desarrollo vegetativo y reproductor en plantas de Ganonema farinosa (Lamouroux) Fan et Wang de las islas Canarias. G.farinosa es una especie relativamente común durante todo el año en algunas localidades de Canarias, aunque en otoño e invierno es menos abundante. Se discuten los caracteres vegetativos más útiles para diferenciar esta especie de las especies del género próximo Liagora Lamouroux. Palabras clave: algas marinas, Ganonemafarinosa, Liagoraceae, morfología, reproducción, islas Canarias.Habit, vegetative and reproductive development have been examined in plants ofGanonemafarinosa (Lamouroux) Fan et Wang from the Canary Islands. G.farinosa is a relatively common species in sorne localities of the Canaries throughout the year, although in autumn and winter is less abundant. Vegetative features useful to differentiate G.farinosa from species ofthe next genus Liagora Lamouroux are discussed. Key words: marine algae, Ganonema farinosa, Liagoraceae, morphology, reproduction, Canary Islands