Distribution and systematics ofBatrachospermum(Batrachospermales, Rhodophyta) in North America. 8a. SectionBatrachospermum:Batrachospermum gelatinosum

Abstract

Eighty-six populations of Batrachospermum gelatinosum were examined from th~'oughout its known range in North America and were compared using nqultivariate morphometrics and image analysis. Morphological variability was as great in individual populations as that measured among locations. Populations pooled for each biome showed a north-south trend in whorl and carpogonium size. The mean measurements for the tundra were significantly smaller in whorl diameter and larger in carpogonium size than those for the coastal plain. B. gelatinosum is widely distributed in North America, having been collected from the north slope of Alaska and Baffin Island in the north to Texas and Louisiana in the south. In addition to the populations analysed, herbarium specimens from North America were examined and confirmed locations in 17 US states, four Canadian provinces and the Yukon territory were added. Three populations, two from the boreal forest (Newfoundland) and one from the deciduous forest (Rhode Island), were examined for morphological variation throughout the growing season. The two Newfoundland poptdations were observed year-round, whereas the Rhode Island population was present only from October to June. Carposporophyte diameter showed a spring maximum in all three populations. In addition, there were seasonal trends in whorl diameter, carposporophytes per whorl and carpogonium length in the Rhode Island population.

Varied phenologies of Batrachospermum gelatinosum gametophytes (Batrachospermales, Rhodophyta) in two low-order streams.

“…In North America, B. gelatinosum has a wide distribution occurring from the tundra in the North to the southeastern coastal plain in the South and appears to be present in streams of varying physical and chemical parameters (Vis et al 1996). The ranges in morphological characters showed some trends when pooled by biome with smaller whorl diameter and larger carpogonium size in the tundra as compared with the coastal plain.…”

“…The ranges in morphological characters showed some trends when pooled by biome with smaller whorl diameter and larger carpogonium size in the tundra as compared with the coastal plain. In that same paper, the researchers showed that specimens from Newfoundland and Rhode Island had almost as much variation in various morphological characters measured throughout the year in three streams as was recorded across the geographic range (Vis et al 1996). A phylogeographic study of this taxon in eastern North America found little genetic variation throughout most of its geographic range, but again specimens were plastic in their morphology (house et al 2010).…”

“…Batrachospermum gelatinosum (L.) DC. is the nominate species of the genus and has been noted from locations in both the Northern and Southern Hemispheres (entwisle & kraft 1984;Vis et al 1996). However, it has been shown that specimens attributed to this species from the Southern Hemisphere are a morphologically similar, but distantly related species, B. pseudogelatinosum (Vis & entwisle 2000).…”

Macroalgas em nascentes e arredores de riachos na região noroeste do estado de São Paulo

“…Geralmente, por representarem sistemas geograficamente isolados, as nascentes podem apresentar numerosos táxons endêmicos, como, por exemplo, de macroalgas (e.g. Vis & Sheath 1996). Contudo, de acordo com Necchi Júnior (1992), esta flora não é tão diferente daquela encontrada em ambientes de águas correntes.…”

“…Estudos ficológicos envolvendo nascentes são escassos mundialmente, sendo que, os poucos existentes se concentram na América do Norte (Whitford 1956, Leake & Leake 1961, Vis & Sheath 1996, Sherwood & Sheath 1999, Sherwood et al 2000 …”