The Corallinaceae (Rhodophyta) from the Ross Sea (Antarctica):: a taxonomic revision rejects all records except Phymatolithon foecundum

A study was carried out to determine the status and disposition of Corallinaceae recorded front the Ross Sea (Antarctica), viz. Clathromorphum lemoineanum, Leptophylum coulmanicum, L. laeve and L. foecundum. A re-examination of the type of Lithothamnion coulmanicum (basionym of Leptophytum coulmanicum) showed that it is referable to the genus Phymatolithon because it possesses epithallial cells whose outermost walls are rounded to flattened and meristem cells that areas short as or shorter than their immediate inward derivatives. Such characters were also evident in specimens from McMurdo Sound. Moreover, because all the specimens studied had a conceptacle chamber roof c. 300 mum in diameter, a thallus thickness of up to 1 mm, and buried old conceptacles, they are conspecific with P. foecundum. Studies of specimens from Terra Nova Bay identified as C. lemoineanum and of specimens from Franklin Island identified as L. laeve showed that they should all be referred to P. foecundum. Furthermore, judging, by the description and illustrations given by Zaneveld & Sanford [Blumea 26: 205-231 (1980)]. records of P. foecundum (as L. foecundum) from Cape Hallett and Moubray Bay can be confirmed. Therefore. P. foecundum is the only member of Corallinaceae confirmed to occur in the Ross Sea (Antarctica).