Vegetative and reproductive morphology of Dudresnaya georgiana sp. nov. (Rhodophyta, Dumontiaceae)

Abstract

D. georgiana sp. nov. is described from subtropical waters on the continental shelf off Georgia, USA. The 11th species currently recognized in the genus and 5th from the North Atlantic, it differs from other species in having many indeterminate axes which do not form clearly defined macroscopic branches. This results in a villose, tufted appearance. The organization of determinate branchlets is more complex than reported for other species; up to 5 lateral filaments are formed by the basal cell of a branchlet. The carpogonial and auxiliary cell systems are similar to those of several other species of Dudresnaya. A review of reproductive systems in the genus and auxiliary cell branches in particular suggests an homology of apparently accessory reproductive branches with vegetative branches.