Dotted Thyme-moss, or Round Moss
Or it might be Rhizomnium pseudopunctatum. Or even a third option, Rhizomnium magnifolium, although there are no dots for Fife in the BSS book and it seems to prefer a montane habitat.
I found this one in the summer, in a very dried-up Ghouls Den (Goales Den, in the New Statistical Account). But didn’t take any back with me to study – mistake.
It seems most likely to be Rhizomnium punctatum, but it’s difficult to be sure without another look. All three options have an untoothed “differentiated” border. The key things to look for seem to be the rhizoids, and capsules.
Punctatum – tufts of large rhizoids at the leaf axils, but no slender rhizoids. Capsules frequent in autumn and winter (4-5 mm long, setae 2-3 cm).
Pseudopunctatum – has the coarse rhizoids at leaf axils, but also “numerous slender rhizoids along the internodes, forming a close felt”. Best seen on younger parts of the stem. Capsules frequent in winter and spring (3.5 mm long). Male and female together.
Magnifolium – not known to produce capsules in Britain. Male and female on different parts of the shoot.
Frustrating that the book doesn’t describe the male and female inflorescence for Punctatum. But I found out elsewhere that it’s dioecious which I should know by now means that male and female are on separate plants.
Punctatum has the leaf border thickened, but Pseudopunctatum doesn’t, although it’s still “differentiated”.
So, all in all, more work required, i.e. another visit to Ghouls Den – but not sure how possible this will be, now that water levels are back to normal.
Update October 2019
Found the same (I think) moss growing on a damp shady bank and a log end in Maspie Den, Falkland Estate. I took some home and think it fits best as Rhizomnium punctatum, in terms of rhizoids and the way the nerve goes right to the tip and sometimes slightly protrudes.
October 2021
Found it in Kenley Den and got some not very good pictures of the rhizoids.
Learning about Mosses 