Biology and taxonomic identity of Erythroglossum lusitanicum (Delesseriaceae, Rhodophyta) from the Iberian Peninsula.

Erythroglossum lusitanicum was originally described from sterile and tetrasporophytic material. The apical organization and the sexual structures have considerable relevance for classification of Delesseriaceae, and these are described here for the first time in this species. The range of morphological variability in some species of the genus Erythroglossum in Atlantic Europe has been broadened, requiring a revision of the taxonomic identity of E. lusitanicum. Reproductive characters observed in E. lusitanicum include: 1) procarps scattered over the blade surface and composed of a supporting cell bearing two 4-celled carpogonial branches and a single group of sterile cells; 2) carposporangia formed in chains; and 3) spermatangial sori consisting of two layers of spermatangial mother cells bearing spermatangia. These features, together with the Phycodrys-type apical organization, are in accordance with those described for the genus Erythroglossum. The main taxonomic features of E. lusitanicum that distinguish it from congeners in Atlantic Europe are thallus growth that occurs in each blade by means of a single apical cell located in the tip, and its turf forming habit. [ABSTRACT FROM AUTHOR]