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DASYA ROSLYNIAE SP. NOV. (DASYACEAE, RHODOPHYTA), WITH A DISCUSSION ON GENERIC DISTINCTIONS AMONG DASYA, EUPOGODON, RHODOPTILUM , AND POGONOPHORELLA 1
Author(s) -
Millar Alan J. K.
Publication year - 1996
Publication title -
journal of phycology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.85
H-Index - 127
eISSN - 1529-8817
pISSN - 0022-3646
DOI - 10.1111/j.0022-3646.1996.00145.x
Subject(s) - biology , apex (geometry) , genus , taxon , apical cell , type species , dorsum , botany , type (biology) , key (lock) , zoology , paleontology , ecology , anatomy , genetics , cell
Dasya roslyniae sp. nov. (Dasyaceae, Rhodophyta) is described from subtidal habitats at Split Solitary Island (30°14′S, 153°11′E), New South Wales, Australia. The new species is distinct within the genus due to its strongly compressed and secondarily bilaterally branched axes, differing from the majority of Dasya species that are terete and secondarily radially organized. Pseudolaterals are quickly caducous on ventral and dorsal (transverse) surfaces but are persistent on lateral surfaces for short distances from the apex, leaving the bulk of the plants flattened and denuded. Its gross morphological characters are thus similar to those displayed by the genera Pogonophorella, Eupogodon (formerly known as Dasyopsis) , and Rhodoptilum. Characters used for separating these genera and Dasya are, in some cases, overlapping and in need of critical evaluation. To the primarily radially organized taxa, determined by examination of divisions of the apical cell, are placed species of Dasya , six species now included in Eupogodon , and the type and only species of Pogonophorella californica. Examination of the activity of the apical cells of Eupogodon planum and Rhodoptilum plumosum , the type species of their genera, confirms the primary bilaterality of these two genera, and the traditional defining feature of Eupogodon (lack of discernible pericentral cells in cross‐section of indeterminate axes) is shown to be untenable. A secondary character that would separate Eupogodon and Rhodoptilum is the polysiphonous bases of otherwise monosiphonous laterals (pseudolaterals) in Eupogodon and the monosiphonous bases in Rhodoptilum .