I've been pottering around Craig Cerrig-Gleisiad a few times over the last couple of weeks. Once with the Gloucestershire group, but it got me hooked and I went back. I collected this 'Brachythecium' on a big boulder at the base of the cliffs at SN969221. Thought it was Sciuro-hypnum populeum, but it doesn't have the long nerve. So then I wondered about B. velutinum - which it seems quite close to, but is this the right habitat?
I'm struggling to get it to fit anything else so any help you can give would be most welcome.
Sorry, I don't have any images of it in situ, but this is my specimen, dry. Not much change when moist although the leaves do look slightly concave.
It has capsules though they have lost their lids; however I can see the seta is definitely papillose at the top, though it appears smooth below.
Branch leaves are similar to stem leaves though slightly narrower. Here's one of each:
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| Stem leaf (x40) |
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| Branch leaf (x100) |
Most leaves - both branch and stem - have this long, twisted leaf tip.
Leaf margins are smooth to faintly denticulate. Mid-leaf cells are quite long and narrow. Not sure if you can make out the measurements but they're 52 - 80 (110) x 5.5-8µm.
Leaf bases mostly have this brown colouration and don't seem to be decurrent (this is half a leaf, split down the nerve on the left).
I'm starting to wonder if it's just an odd B. rutabulum, but don't think it is. So Brachytheciastrum velutinum? Any other suggestions? Maybe not even Brachythecium?
Thank you all.
Brachthecium rutabulum - leaf shape is quite variable. Good pointers are the slightly pleated leaves and the seta which is coarsely papillose, but only at the top. Also the shiny yellow-green colour and the chaffy appearance when dry are indicators. Some forms can look a bit like B.glareosum (see earlier post on this). Brachythecium velutinum is quite slender and the seta are papillose throughout.
ReplyDeleteThanks Charles. I didn't realise B. rutabulum seta is only papillose at the top - probably never looked closely. I compared with a couple of B. velutinums which were, as you say, much more slender - but thought this might be variable too. And I have seen B. rutabulum with some twisted leaf tips before, but never with all of them twisted like this. Live and learn! At least in the current situation I can spend time looking properly at the specimens I've gathered.
ReplyDeleteThhanks for sharing this
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