Observations of the reproductive morphology of the red algal genus Ochtodes J. Agardh (Rhizophyllidaceae, Gigartinales)

Abstract

Abstract The development of the female nemathecium of the genus Ochtodes is followed. Carpogonial, auxiliary cell, and vegetative branches collectively form the nemathecium. The initials of these branches are terminal cells of lateral determinate branches. Structures described by Joly & Ugadim (1966) as carpogonial branches are interpreted as hair cells. The carpogonial branch, four-celled auxiliary cell branches, and post-fertilisation events leading to the formation of the carposporophyte are described for the first time for the genus. Procarpic and non-procarpic assemblages are present in the same plant. The evolutionary and taxonomic significance of the presence of these assemblages is discussed. Based on the structure of the auxiliary cell branch and post-fertilization events leading to the formation of the carposporophyte, the genus Ochtodes appears to be most closely related to Peyssonnelia and Cruoriella of the Peyssonneliaceae.