The Dumontieae, a resurrected tribe of red algae (Dumontiaceae, Rhodophyta)

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Abstract
Several monophyletic groups of taxa were produced by a cladistic analysis of all species belonging to the red algal family Dumontiaceae (Gigartinales). One of these groups is recognized here as the tribe Dumontieae. It consists of the species of Dumontia, Cryptosiphonia, Hyalosiphonia, MASULAPHYCUS gen. nov. [based on M. irregularis comb. nov. (Parlonia irregularies Yamada)]. Neodilsea, and Dilsea, all found in the North Pacific with some spillover into the North Atlantic. Dasyphloea insignis, the only species of an endemic, southern Australian genus, is included in the Dumontieae with reservation. An eplicit hypothesis of phylogenetic relationships, based mostly on morphological features, is presented for all species of the Dumontieae. The primitive condition in the tribe is hypothesized to be a relatively short carpogonial branch (no more than 11 cells long), an anticlinal-periclinal pattern of division of periaxial branches, an alternation of isomorphic generations, a lateral trichogyne, the carpogonium not always dividing after fertilization, relatively large tetrasporangia, and an immediate discal type of spore germination pattern. Trends in the Dumontieae include a change from a uniaxial, cylindrical, branched habit to a ''multiaxial'', foliose habit and development of a large gonimoblast fusion cell and large sporangia that diminish in size with evolutionary advancement within the tribe. No single character uniquely distinguishes the Dumontieae. Current placement of species in genera is upheld, except for ''Farlowia'' irregularis, for which a new genus is proposed. The genera Dilsea and Neodilsea are polyphyletic in the analysis, but no taxonomic changes are proposed at this time.