Taxonomy and reproduction in Australian species of Diliphus (Dictyotales, Phaeophyta)

Abstract

Eight species of Dilophus are recognised for Australia. Detailed descriptions are given for five species, D. fastigiatus, D. gunnianus, D. intermedius, D. marginatus and D. robustus. D. moniliformis and D. crinitus from Western Australia and D. decumbens from subantarctic Macquarie I. remain poorly known. Sporophytes and gametophytes are reported for the five species providing first records of sporophytes of D. robustus, female gametophytes of D. intermedius, and both male and female gametophytes of D. robustus and D. marginatus. The arrangement and structure of sporangia and gametangia have been intensively studied and many reproductive characters not previously used in species discrimination have been incorporated into species' descriptions and used to develop species' concepts. Species are delimited on the following combination of characters: arrangement, size and structure of sporangia, arrangement and structure of gametangia, and the number of medullary cell layers.