Parc Lodge Wood bryology

Graham and I needed to visit Parc Lodge Wood - in the Sugarloaf Woodlands SAC of NW Monmouthshire - to see whether water abstraction from a series of springs has been damaging the woodland.  This gave me a chance to look for bryophytes at a SSSI that I had last visited in August 2000, when I found 66 species.  This time I missed Trichocolea, Lophozia ventricosa and Thuidium delicatulum, but added 37 species to the site total: a useful visit!

The Old Sessile Oak woodland is rather impoverished compared with its analogues in the Nedd & Mellte valleys or Meirionnydd (!) but holds locally abundant Dicranum majus and occasional Rhytidiadelphus loreus and is therefore more western feeling than most woods in Monmouthshire.  The stream in the valley bottom supported some Lejeunea lamacerina, Heterocladium flaccidum and Jungermannia pumila, all of which are uncommon in the county, and a spring held Sphagnum fimbriatum and S. palustre.  I completely missed epiphytes in 2000 (or perhaps there weren't any), so 10 common species such as Metzgeria furcata and 3x Ulota were new.

As we left the woodland we passed a small spring with Anagallis tenella, Briza media, Ctenidium molluscum, Campylium protensum and Fissidens adianthoides, and then a stream with Marchantia polymorpha, Scapania irrigua, Dicranella staphylina and Bryum violaceum.  The tetrad needs another visit, to a churchyard and bridge in the east of the square, but today's visit has bumped it up above the 100 mark.

Colura in SE Wales

Once upon a time... not so long ago... I got very excited about Colura.  Back in 2001 there were just two records of this species from south Wales: one made by the BBS in Hensol Forest in the late 20th century and one by Martha Newton in the Nedd-fechan valley in ca. 2000.  Graham and I paid homage to Martha's colony in summer 2001, and we were really impressed that such a tiny, rare, beautiful thing could really be in south Wales (and that someone could actually find it).  Then in August 2001, to my amazement, I spotted some tufts of Colura on 2 Ash trunks in the Yew Tree Wood near Dingestow.  I phoned Graham, incoherent with excitement, astonished that such a rare liverwort could be here.

Fast forward to 2016, and the situation has changed completely.  In 2002/03 I started bryo recording in Brechfa Forest, discovering vast colonies of Colura on willows in the conifer plantations there.  It proved to be widespread, and more or less ubiquitous in the upland-edge plantations of Wales, as Charles and Hilary are ably demonstrating in Neath - Port Talbot.  However, it remains pretty scarce in Monmouthshire, and I have only seen it in VC35 on three occasions since that exciting day in 2001: twice in the west and once in the east.  Graham asked me a couple of days ago whether it's still in the Yew Tree Wood, and I didn't know.  Sure enough, it is - I revisited the site yesterday lunchtime and found Colura on several Ash trunks in the original area, alongside loads of Cololejeunea minutissima, Radula complanata and Metzgeria spp., plus a patch of Lejeunea cavifolia.

This rambling tale is a way of letting relative newcomers to bryology know how much things have changed, even during my bryological career!

Plagiochila query from Cwm Clydach, Kidwelly SSSI

Below are some images of two Plagiochila samples collected on Monday, close to the second (new?) Sticta canariensis site in the upper section of the gorge (main site shown above). Growing on a small dark cliff face, were scattered shoots of a tiny Plagiochila that I took to be depauperate spinulosa, as there were some nice patches of the latter only 1m away. However, as it shows a casual resemblance to exigua, I thought pass it by for discussion / to highlight the potential for confusion.

First up, healthy spinulosa specimens (note the long decurrent antical margin):

Now the troublesome specimen, associates including Trichostomum tenuirostre, Heterocladium flaccidum, Lejeunea lamacerina, etc. (note the 'mostly short decurrent antical margin - but probably not as short as it should be, plus the leaves may be a bit too wide and broad-based?):

To get an idea of size, the following image shows a shoot along with Heterocladium flaccidum, Lejeunea lamacerina and the Trichomanes speciosum gametophyte:

Location of the diminutive Plagiochila, it being more well-tucked in than the image might indicate:

Plus the reason for me being at this lovely site, the cyanobacterial morph of Sticta canariensis:

Lejeunea patens (Pearl Pouncewort)

Lejeunea patens is uncommon in VC41. As far as I can tell, the most recent record was made by Sam and Graham (2010) for Sgwd Gwladys in the Pyrddin Valley, where it grows as an epiphyte on Oak. The only other records (1960s) are for Craig y Llyn, where it grows on rock. So it was nice to find these plants growing as epiphytes on willow in the conifer plantation above Pentreclwydau (between Resolven and Glyn Neath).
Lejeunea patens has a distinctive, large lobule that makes a sharp, acute angle with the leaf, which differentiates it from the much more common L. lamacerina (the most common Lejeunea in NPT).

Lejeunea cavifolia has smaller lobules, but the 2 species are best distinguished by their cellular oil bodies. While cavifolia usually has a large number (25+) of small oil bodies, patens has few (up to 8) and they are larger.

The colonies have a distinct pale lustre in certain light, so the common name is rather apt.

Lejeunea query resolved

Well I finally had another attempt at sectioning the Lejeunea stem and managed this result. <=6 medullary cells seems to be a good pointer for mandonii. I'm still not terribly convinced but wonder if there's a referee for this group?

stem in top half of section

Paviland Lejeunea query

I'm assuming this is just poorly grown lamacerina, but there appears to be a hint of mandonii about it. My first attempt at sectioning the stem failed, but I'll give it another go. It was found growing in tightly grazed turf, semi-shaded (n-facing) in the lee of a rocky Limestone outcrop on the cliffs at Paviland yesterday. The widest shoots are 0.8mm wide, which is probably just a bit too much for mandonii, but the leaf shape seems good on some shoots, so thought it was worth posting for an opinion.

Also a new colony of Entosthodon pulchellus at the head of the gulley at Foxhole.

Lejeunea query

Not having a copy of Paton is a pain when it comes to those liverworts that need checking microscopically. I collected this Lejeunea yesterday from acidic sandstone rocks alongside a wooded hillside stream above Treforest (ST09V), growing near R. aciculare and S. plumosum. Most leaves have only a few oil bodies but some towards the base of the shoot (first photo) have 10+, but I think it must be lamacerina or patens. The lobules are fairly big and the angle between lobule and main lobe looks quite acute, so I wondered if this might be patens?

 Thanks as always for any help.
George