Morphology, vegetative and reproductive development of the red alga Portieria hornemannii (Gigartinales: Rhizophyllidaceae)

Earlier descriptions of the Indo-Pacific red alga Portieria hornemannii lacked detailed information on its vegetative and reproductive development and morphology. An in-depth treatment is presented on the development of the uniaxial thallus and the formation of male, female and tetrasporangial nemathecia. Post fertilization events and carposporophyte development is described, confirming Kylin's presumption on the development of connecting filaments between the carpogonium and the auxiliary cell following fertilization. Phylogenetic analysis using chloroplast encoded rbcL and nuclear ribosomal LSU gene sequences, including members of Rhizophyllidaceae and their close relatives suggests a monophyletic family. Contarinia is resolved as the sister taxon of a clade uniting Nesophila. Ochtodes and Portieria. The relationships among the latter genera remain largely unresolved. (c) 2011 Elsevier B.V. All rights reserved.