Thursday, 27 April 2017

Habrodon at Merthyr Mawr

I was at Merthyr Mawr today for a site meeting with Duncan Ludlow, and having mentioned Habrodon perpusillus while we were chatting in the car park Duncan offered to show me the sycamore which hosts this rare moss. Despite Duncan leading me to the exact multi-trunked tree I couldn't spot it, but I nipped back afterwards for another look and found numerous small patches on one of the trunks (circled yellow in photo below).

I was struck by the superficial similarity to young Cryphaea, as Sam and Barry have commented previously.

The good news is that Duncan has removed the Holm Oak that was shading the host tree, and plans to fell further Holm Oaks slightly further away. Hopefully this will allow enough light onto the sycamore trunk for the Habrodon to persist.


  1. I guess it must be on other trees too, so now your eye in ;-)
    Did you ask Duncan about Leptodon?

  2. Duncan has now sent me Sam's 2008 report on Habrodon at MM. Sam checked all the trees in the area around the car park and only found it on three sycamores growing together at the base of the 'big dipper'; the trunk which I found it on had the most patches. So it is very localised at the site - but you're right, it is useful to have got my eye in a bit for this species, as I now feel a bit more confident that I might spot it at other sites if it is present (Porthkerry would seem worthy of a search).

  3. Good luck, I'm always hopeful it will be found on Gower...

    1. Chris Forster Brown3 May 2018 at 16:35

      I had a look at the Fonmon site I'd discovered a couple of years ago. Went back there around 20th April and Habrodon is in quantity on at least three trees (forgot to look at tree species!). There are many patches, especially on one tree. There is also Cryphaea at the site and the difference becomes more obvious when you see the two together. Al the Cryphaea patches have some fruiting, at lest close by, whereas Habrodon has none. I've checked a very small quantity under the microscope and it also has gemmae. When growing en masse, the shoots are markedly homomallous (i.e. growing in same direction). Also at this site is Leptodon in quantity. Big patches on some trees. I recorded it on sycamore, beech, ash and oak. One tree has both species. Would be worth a further search in this area generally. I have looked at Porthkerry previously but never found either. Southbya is found in several small populations on the cliffs round here. would be happy to show anyone the Habrodon/Leptodon site. Chris Forster Brown (novice blogger)