Cwar Du - a boost to SN90F

I spent my lunch hour (well actually a split 20 minutes before and after my main work) recording in SN90F, east of the A4061 between Treherbert and Craig y Llyn.  This was slightly pointless because there were already over 70 species recorded from the tetrad, but it looked like good ground as I drove past and I thought I'd add something.  In the end I found about 95 species, and there were 14 on the previous list that I didn't see (mostly plantation & track species), so the tetrad is now nicely over the 100 mark and can probably be regarded as 'done'.

First stop was a small, sealed-up, graffiti-covered building surrounded by sculptures, where I recorded various ruderals including Tortella tortuosa, Orthotrichum cupulatum and Schistidium apocarpum on concrete.  A yomp up through scree with 4 cushions of Scapania gracilis led to the Cwar Du cliff base at 450m altitude, where Ditrichum zonatum new for Glamorgan awaited me.  Nearby were Campylopus atrovirens, a small form of Gymnocolea inflata, some Lophozia sudetica, and a bit of Rhabdoweisia crispata.  A rowan added Cololejeunea minutissima and other common epiphytes to the list.

After I'd finished my work near Glyncorrwg I stopped briefly at Nant y Bwlch, just down from Cwar Du, to add some stream mosses to the list.  Hygrohypnum ochraceum and Hyocomium armoricum were present in the stream, Ptychomitrium polyphyllum was on boulders, Polytrichum alpinum was on a low cliff, and slight base enrichment was indicated by a few shoots of Trichostomum brachydontium among Amphidium mougeotii.  Perhaps the highlight of this area was some Lophozia bicrenata with perianths on humus under heather - a thoroughly unpredictable species.

So, a worthwhile stop given that I didn't have time to properly bash an unknown tetrad.

Hercynian Haircap

Oligotrichum hercynicum (Hercynian Haircap) with Pogonatum aloides, Blaengwynfi

This is a relatively common species in quarries and along forestry roads in the uplands of NPT, where it often grows with other pioneers species such as Ditrichum heteromallum, Pogonatum aloides, Pogonatum urnigerum, Diplophyllum albicans, Nardia scalaris and Solenostoma gracillimum.  Most colonies are barren, but very occasionally we see it in fruit. 

Oligotrichum hercynicum in fruit, Bwlch Forest

It is a conspicuous, vivid green moss, difficult to miss and the rather local distribution pattern indicated by current records in the database may be misleading. My guess is that it is scattered throughout the coniferised uplands of VC41, so it's worth targeting in the coming season. Perhaps its apparent absence from Gower is real, or a challenge for Barry!

Distribution of Oligotrichum hercynicum in Glamorgan (Map Mate records, 1km squares)

And while we're on the subject, Ditrichum heteromallum also appears to be rather local or perhaps under recorded in VC41 and apparently absent from Gower. Now is a good time to see it in fruit, which makes its identification a bit easier (at least for me).

Ditrichum heteromallum, Crynant Forest track (29/8/16)

Distribution of Ditrichum heteromallum in Glamorgan (Map Mate records, 1km squares)

Mining for moss

Visits to three Ceredigion lead mines last Friday produced several nice things.  I'll start with 3 showy species: Racomitrium elongatum, Tetraplodon mnioides and Hedwigia stellata.  The Racomitrium is pretty frequent in the Cambrian Mountains and its long reflexed hairpoints are a good pointer (before microscope checking).  Tetraplodon is present on most Mid Wales mines, where it grows on scats and bones.  Hedwigia stellata is surprisingly sparsely distributed in Ceredigion, and the two tufts I saw were on tarmac - the first time I've seen it on this substrate.

 

Prize for smallest and grottiest goes to Ditrichum plumbicola and D. lineare.  The two colonies of D. plumbicola were both "new" - the 15th & 16th sites for this species in Mid Wales - in part because nobody had specifically looked for it on those sites.  The D. lineare was also "new", and was unusual because it's generally found on natural sites in Wales rather than on mines.  Ditrichum plumbicola has blunt-tipped leaves and plane margins, whereas the D. lineare has acute tips and slightly recurved margins.

 

Prize for rarest may go to D. plumbicola, but with a bit of luck I'll be able to confirm that a colony of very toothy Cephaloziella is C. nicholsonii.  This would be only the 5th Welsh locality for this British endemic.  It was growing at the foot of an old wheel pit wall, and it's interesting to note that the first Ceredigion colony was on a wall on Cwmystwyth mine (found by David Holyoak).

I'll add some microscope photos of the Cephaloziella soon. 

Dulais Valley at Coynant

A rain-soaked walk through flushed pasture at SN650069 yesterday returned a modest selection of species of local interest including Aneura pinguis, Aulacomnium palustre, Brachythecium rivulare, Bryum pseudotriquetrum, Philonotis fontana, Riccardia chamedryfolia, Sarmentypnum exannulatum, Scapania irrigua, S. undulata, Sphagnum denticulatum, inundatum, squarrosum, subnitens (photo below) & Straminergon stramineum.

Deep mounds of Nardia compressa (photo above) were abundant in the adjacent river and species of interest along the banks included Dichodontium palustre (photo above), Dicranella rufescens, Ditrichum heteromallum (photo above) & Entosthodon obtusus (photos below).

Note the bordered leaf margins, which rules out all other Entosthodon species with erect capsules.

Another Ditrichum gracile population in a forestry road verge

 Ditrichum gracile  in calcareous gravel of forestry road verge

After Barry's description of the calcicole community on the west side of Mynydd Aberdare, I commented on the occurrence of Ditrichum gracile as a 'nice record for a forestry road verge'. Well, here it is again in a gravelly verge in a very similar community in Japanese Larch plantation near Banwen.

Ditrichum gracile (Banwen) with long silky leaves

The community also included Didymodon ferrugineus, D. fallax, Ctenidium molluscum and Trichostomum crispulum. Other calcicoles that occur in similar verges elsewhere in NPT include Campyliadelphus chrysophyllus, Distichium inclinatum, Encalypta streptocarpa and Jungermannia atrovirens.
The Ditrichum here forms dense turfs in places, so I looked at it closely, particularly in view of recent postings. The occurrence of an obvious tomentum (relatively dense on some shoots) encouraged me to take some specimens back for closer inspection.

 Rhizoids on lower part of D. gracile stem

However, leaf length and general morphology clearly point to gracile, as does the absence of short-leaved, deciduous branches (see Sam's post on 30/1/15). Also, when dry, the long leaves become distinctly flexuose and twist around each other at the tip. This may be a much more reliable character for gracile than the density of the tomentum, which looks like a  more plastic, phenotypic character.

Dry, flexuose and twisted leaves of D. gracile

But this also lends weight to Sam's comments regarding the occurrence of intermediate forms and safety of the split between gracile and flexicaule. 

Ditrichum flexicaule

Following George's photos of Ditrichum gracile from Cefn-onn, here are a couple of pics of D. flexicaule sensu stricto from the tops of limestone boulders at Craig y Cilau.  The lower photo shows the characteristic branches with short, imbricate leaves - D. gracile doesn't have these.  There are problematic intermediates though, and a widespread feeling among British bryologists that this isn't the safest of splits.

Cefn Onn

On Sunday morning I took a quick stomp from Parc Cefn Onn up to the old limestone quarry on the ridgeway north of Cardiff. Virtually the whole walk fell within tetrad ST18S, which must be one of the richest for bryophytes in south-east Glamorgan - a mixture of wooded country park, acid woodland on the lower slopes and limestone woodland and exposed outcrops at the ridgetop. I had a cursory look at the bryos back in 2011, and a few others (including Peter Sturgess, who's now signed up to this blog - hello Peter!)  have done some recording too, but it's never had a thorough survey. There's also some conifer plantation within the same tetrad, on the Caerphilly side of the ridgeway, which hasn't been looked at.

The wooded limestone outcrops below the quarry support some impressive carpets of Anomodon viticulosus (see photo above), plenty of Neckera crispa and Tortella tortuosa, and smaller quantities of Eucladium verticillatum and Cirriphyllum crassinervium.

Neckera crispa

The quarry itself looked fairly horrific on first impression - it was being used for overwintering cattle and you can see the effect this has had in the photo below.

The quarry sides were undamaged, however, and produced a good range of calcicoles including Aloina aloides (fruiting), Ditrichum gracile and Trichostomum crispulum.

Ditrichum gracile

An area of short limestone turf above the quarry produced Brachythecium glareosum, Campylium protensum, Rhytidiadelphus triquetrus and, more surprisingly, a small patch of Hylocomium splendens (presumably in an area that has been leached).

Finally, an area of hilltop limestone outcrops to the west of the quarry (photo below) added Pseudocrossidium revolutum as well as more Ditrichum gracile. I found Dicranum bonjeanii in this area in 2011 but couldn't relocate it on Sunday.

Thanks to Peter Sturgess for suggesting the ID of Ditrichum gracile, which he'd found in the same area. I was put off the scent by the small size of the patches at Cefn Onn (only 2cm tall), but am pretty sure this is what they are.