Monday, 9 February 2015

Llandaff Cathedral

If a bryologist were visiting my home tetrad (ST17P), the first place they would probably head would be Llandaff Cathedral and the attached graveyard. It might seem odd, then, that I'd never done any mossing there until Saturday. This was because Barry had paid a visit in 2013. However, Barry's visit was quite fleeting so it seemed worth another look, and I didn't have access to the car so my options were limited to somewhere close to home.

I was particularly hoping to relocate two calcicoles recorded by Barry which I'd never seen: Scorpiurium circinatum and Didymodon umbrosus.

The Scorpiurium proved easy to find and was fairly frequent around the base of the cathedral walls on the northern, southern and eastern aspects. It also occurred on some low walls nearby, as in the pic below.

Scorpiurium circinatum

The Didymodon was a different matter - I thought I'd failed to find it, but on checking my samples at home I did find a couple of tiny stems which could, perhaps, be this species - see photos below. It looks fairly similar to Barry's photo from 2013, but it seems to lack the basal hyaline cells mentioned in Smith so I think it must be something else (not just a wretched Schistidium I hope!).

The cathedral walls also added two species for the tetrad: Tortella tortuosa and Pseudocrossidium revolutum.

I then had a look at the graveyard, which added eight more species for the tetrad including Cirriphyllum piliferum, Didymodon tophaceus, Brachythecium populeum and Homalothecium lutescens.

Llandaff cathedral graveyard
The most surprising find, though, was a small patch of fruiting Zygodon conoideus on a sloping grave (gemmae checked microscopically). Has anyone else seen this species on stone?
Grave supporting Zygodon conoideus
Zygodon conoideus on gravestone, mixed with Frullania dilatata

Finally, this Schistidium was growing on a semi-shaded wall top near the cathedral. The leaves have short, toothed hair points and the whole plant is quite large (stems to 5cm). I'd have thought this was apocarpum rather than crassipilum based on the short hair points, but the leaves aren't falcate. Any suggestions welcome, thanks.


  1. George, from what I remember that looks different to the material I collected. I'll dig out my pictures and post any that might help when I get a chance - did you collect it from the same spot I saw it?

  2. PS. Well done on your additions, Pseudo.rev. in particular.
    And no, I don't recall ever seeing conoideus on rock!

  3. Takes the tetrad total to about 82 species - just a little way short of Sam's 217 species in his Dingestow tetrad :-)

    There are three species in your database for ST17P which have the wrong grid ref associated with them - these are the 1950 Wade records from "Radyr Quarry". The grid ref is listed as ST149796, which is in Llandaff North and away from any quarry. Looking at old OS maps the real Radyr Quarry straddled two tetrads (typical!), but was centred on ST140794 which might be the best grid ref to use for the records.

  4. Thanks George - grid ref corrected.

  5. I think I have seen Z conoideus on rock a couple of times, but it is far from typical.

    The Schistidium looks plausible as apocarpum. As it has capsules you should be able to ID conclusively by looking at the exothecial cells under the microscope - all long & narrow in crassipilum vs mostly rather short and broad in apocarpum.

  6. Thanks Sam. I've now checked the exothecial cells and it is conclusively crassipilum.