Wednesday, 18 February 2015

Dulais Valley

Barry's excellent record of Jubula hutchinsiae in the lower Dulais Valley a few weeks ago reaffirmed for me the potential importance of this largely unknown area of NPT. Unfortunately, much of this long valley is flanked by private land and difficult to access. Even where access is possible, navigation is tricky. One stretch of the river at Cefn Coed (near Crynant) provides opportunities for a small amount of exploration. A riverside oak tree here has an interesting assemblage of epiphytes which includes Lejeunea lamacerina and Heterocladium heteropterum. Scattered among the Lejeunea there is a larger liverwort which looks like Jamesoniella autumnalis to me (photos below). Although J. autumnalis is often associated with decaying logs, it does grow on standing oaks in humid valleys (e.g. Nedd Fechan Valley, Brecs). For absolute confirmation I would have liked to have seen some perianths, which I couldn't find. Unfortunately, vegetative J. autumnalis is a bit nondescript and resembles some other liverworts, particularly Jungermannia (or even Saccogyna). The habitat probably rules out Jungermannia and the alternating leaf arrangements looks wrong for Saccogyna (and there are no underleaves). But I might be missing something obvious. Comments appreciated.


  1. The top photo made me think you'd got muddled by Plagiochila, but then I spotted the odd thing you were referring to. The other two photos show it much better. I'm sure it isn't Jamesoniella, having seen it quite frequently in the past (including last month), because the leaves of that are more concave. It also looks wrong for most Jungermannia. One name is fluttering in the back of my mind, in part because of appearance and in part because of habitat - Leiochlaena lanceolata (aka Jungermannia leiantha). It is a very long shot and you'd really need perianths to confirm an ID, but please have a careful look at oil bodies etc and if it's looking promising please send me a fresh specimen. I'm probably getting excited about nothing...

  2. Thanks Sam. Yes, sorry, I should have pointed out that Plagiochila porelloides was also all over the place there and it may turn out to be just an odd form of that in the end. I'll check out your suggestion.

  3. A few observations of material under the microscope. Leaf cells in the range 25 - 35 microns wide. Oil bodies distinctly granular, only 2 or 3 per cell, fairly large, up to 12 x 5 microns. I don't think it's a small, edentate form of Plagiochila porelloides. If it's not Jamesoniella autumnalis, then the probability is that it's a Jungermannia type, but not L.lanceolata. In which case I'm probably stuffed unless we go back and find some fertile material. I've been here before!!!