Monday, 15 February 2016

Rare fungus on Weissia multicapsularis

There aren't many rarer British mosses than Weissia multicapsularis, as it has fewer than 5 known colonies in the World!  Its first Welsh record came from Dingestow in 1981 (when I was too young to appreciate mosses) and it was a thorn in my side, with 15 failed attempts at relocation, until I found my own colony about 1km from the original site in 2008.  I revisited the colony this afternoon and tall, brownish, short-leaved Weissia are frequent over the same area as I marked in 2008, although I completely failed to find any sporophytes to confirm the ID.  The site seems utterly mundane - a steep bank in improved pasture - but also supports Acaulon muticum, Weissia squarrosa and lots of a small Fissidens that looks likely to be F. crispus.  I suspect it has never been overly fertilised because it is too steep, and a combination of a SW-aspect, grazing and slumping prevent takeover by vascular plants.

Anyway, one patch of Weissia had a little orange fungus growing at its base.  I figured that a fungus growing on Weissia multicapsularis could be pretty rare, so I carefully collected the fungus and 3 stems of the moss for identification.  It looked rather ill-defined compared with most Octospora that I have seen, perhaps because of the membranaceous margin (something mentioned on the excellent Bryoparasitic Pezizales site  Under the microscope it had remarkably lobed asci containing 8 strongly warted spores.  A check on the Pezizales website suggested the only fungus recorded so far from Weissia species is Lamprospora tuberculatella, which has spores that are identical to my specimen.  From what I can see on-line, there are no previous British records, so a very rare moss may support an even rarer (in British terms) fungus.


  1. The location really does look quite unremarkable. I'll be taking a closer look at such banks whenever I encounter them in the future, though I'll do well to match your diligence.

  2. Indeed. We must miss species which grow in these kinds of habitats during our square bashing, as it's not exactly the kind of place you would think of targeting for bryos.

    I've been checking large Funaria patches on bonfire sites for parasitic fungi, but without luck.