A taxonomic account of species in the tribe Spongoclonieae (Ceramiaceae, Ceramiales, Rhodophyta) reported from Atlantic and Pacific Mexico

Abstract

The tribe Spongoclonieae (Ceramiaceae subfam. Spongoclonioideae) is represented on the Atlantic and Pacific coasts of Mexico by two genera: Pleonosporium with eight species and Spongoclonium with a single species. Pleonosporium boergesenii and P. borreri are both new records for Atlantic Mexico. Known in Pacific and Atlantic Mexico, P. rhizoideum has the widest distribution, while P. pygmaeum and P. vancouverianum have only a few records in the study area. Pleonosporium mexicanum is found mainly in tropical Pacific Mexico, and P. globuliferum has a discontinuous distribution in the Gulf of California and then in Salina Cruz, Oaxaca. In the case of P. squarrulosum morphological and genetic comparisons are needed to verify its presence in Mexico. The report of Spongoclonium caribaeum from intertidal Veracruz (Gulf of Mexico) represents the second record of this species for the Atlantic coast of Mexico. Detailed descriptions, information on nomenclature, collections studied, distribution and habitat are provided for each of the species. Measurements of vegetative characters and reproductive structures provide a consistent basis for identifying Atlantic and Pacific Mexican species of Pleonosporium and Spongoclonium.

Australasian Lophothamnion J.Agardh Aligns Genetically with Pleonosporium Nägeli (Wrangeliaceae, Spongoclonieae): New Species from the Western Atlantic

“…Plenosporium borreri was reported from the warmer, more southern waters of North Carolina (Williams 1951), but Schneider & Searles (1991) were unable to locate Williams' vouchers of this species. Because of its similarity to P. boergesenii (A.B.Joly) R.E.Norris (Schneider 1975, as Mesothamnion boergesenii Joly), Schneider & Searles (1991) excluded P. borreri from the southeastern U.S. flora, although Mateo-Cid et al (2018) recently reported it from the Atlantic coast of Mexico.…”