Northwest Lichenologists

Niphotrichum or Racomitrium?

  • 27 Dec 2018 8:34 AM
    Message # 6973628

    Hi folks,

    This post is for my fellow bryonerds.

    I'm wondering if anyone can tell me what the most recently accepted name would be for Niphotrichum elongatum (formally Racomitrium). The Flora of North America Vol 27 uses Niphotrichum and refers to this publication for details: Ochyra, Ryszard. Census catalogue of Polish mosses. Vol. 3. Polish Academy of Sciences, Institute of Botany, 2003.

     I've been assuming Niphotrichum the most widely accepted name, going by Flora of NA (2007). However, I recently found this article: 


    Stech, Michael, et al. "Molecular species delimitation in the Racomitrium canescens complex (Grimmiaceae) and implications for DNA barcoding of species complexes in mosses." PLoS One 8.1 (2013): e53134

    which states that: "Morphologically distinguishable groups have been treated either at different taxonomic levels within a broadly defined genus Racomitrium, or as four separate genera [13], which led to considerable changes in species names. For example, the R. canescens species complex was treated as genus Niphotrichum [13]. First molecular phylogenetic reconstructions, however, supported a monophyletic Racomitrium clade [14][15].

    So that paper lumps Niphotrichum back into Racomitrium based on DNA.

    What I'm wondering is if their is a broad consensus among bryologists to use Niphotrichum? Or are we back to grouping these species in Racomitrium? I suspect the answer won't be so clear but I thought I would put it out there. 

    Thanks for your help!


  • 28 Dec 2018 8:07 AM
    Reply # 6975142 on 6973628
    Bruce McCune (Administrator)

    I had originally used the Racomitrium splits in my Common Mosses... book ( based on the Flora of North America and others, but then I read the DNA evidence you cite and happily reverted to using Racomitrium. So at the last minute in producing the book I switched back to Racomitrium. A nice practicality about this is that Racomitrium is an easily recognized genus, while the splits in Racomitrium made it hard to tell the genus without detailed microscopic study.

    The situation is similar in ways to what we lichenologists experienced with Cetraria. Over the last couple of decades most of the lichenological community abandoned Cetraria as formerly understood in favor of Tuckermannopsis, Vulpicida, Allocetraria, Flavocetraria, etc. These were based on color and a few morphological features, which turn out to be misleading about the phylogeny of the Cetraria group of fungi. So now it seems most logical to either use Cetraria in a broad sense or to adopt the two main genera, Cetraria and Nephromopsis. (For more on that see the NWL post from a while ago -- Divakar et al 2017 in Resources | Recent publications... )

    The similarity between the fates of Racomitrium and Cetraria also extends to resistance to reverting to the broader names. Note that the North American lichen checklist is still using Tuckermannopsis despite more than a decade of accumulated evidence that the genus makes no sense! And now that the Racomitrium splits are preserved in the Moss Flora of North America, they will be around for a long time.

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