MORPHOMETRIC ANALYSIS OF BATRACHOSPERMUM SECTION BATRACHOSPERMUM (BATRACHOSPERMALES, RHODOPHYTA) TYPE SPECIMENS

Type and historically important specimens of 46 species and infraspeci fic taxa from Batrachospermum sect. Batrachospermum were examined. Of these, 48 specimens of 33 taxa were compared using multivariate morpho metrics and image analysis. Nine species from the cluster analysis and one other species are recognised: B. anatinum, B. arcuatum, B. boryan um, B. carpocontorum, B. confusum, B. fluitans, B. gelatinosum, B. het erocorticum, B. pulchrum and B. skujae. B. ectocarpum is considered to be synonymous with B. anatinum, rather than with B. boryanum or B. ar cuatum as has been proposed by previous authors. The illegitimately na med species B. helminthosum Sirodot (non Bory) is referable to B. conf usum as are B. crouanianum and B. fruticulosum. No varieties of B. gel atinosum could be supported and numerous taxa including B. pyramidale, B. densum and B. decaisneanum are synonymised within this species. Th e taxa in sect. Batrachospermum are separated on the basis of whether they are monoecious or dioecious, carpogonium size, and the presence o r absence of (1) spermatangia on the involucral filaments, (2) irregul ar cortication, (3) monosporangia, (4) well-curled fascicles and (5) s econdary fascicles. Other qualitative characteristics previously used to separate taxa in this section, such as carposporophyte position, ho urglass-shaped cells of the carposporophyte-bearing branch and brown c ortication, were found to be too variable for use as taxonomic criteri a. Additionally, the quantitative characteristics overlapped among spe cimens and were only useful in distinguishing B. fluitans from B. anat inum. Revised descriptions and a synoptic key of the species are provi ded.