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.

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 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