Rhodochorton purpureum (Lightfoot) Rosenvinge (Ar/A)

This species forms reddish turfs under a variety of algae in the low to lower mid intertidal zone, although under dark damp overhangs or in the openings to coastal caves with some freshwater input populations can be found. This species has sparsely branched uniseriate filaments that are relatively thin (8-14 um), but that can reach a cm (+) in height (Image A). The plastids are many and discoid in each cell and no pyrenoids are present with the only reproduction noted in our flora being the cruciate teatrasporangia, which are typically formed in clusters (Image B) (spermatangia were noted in culture for a plant collected in Baffin Island, NU).

Although considered widely distributed, there are numerous genetic groups and taxonomic work is needed. This morphospecies appears diverse in the NW Atlantic (~4 genetic groups) with another genetic group extending from BC, through the Arctic and into the NW Atlantic. As a morphospecies in the NW Atlantic we have records from the northern tip of Baffin Island, NU, to southern NB, but the range is likely to extend further south (e.g. a specimen was generously provided by C.W. Schneider from CN, but PCR amplification failed).

EGWS000384001a copyImage A. Specimen collected mid intertidal on rock under Ascopyllum (Letete exposed biodiversity site, Bay of Fundy, NB; EGWS000384).

EGWS000384001b copy.jpgImage B. Whole mount of cellular details and tetrasporangial clusters (EGWS000384).