Cystopteris dickieana Dickie's Bladder-fern RRR DDD N
This plant occurs in a sea cave near Aberdeen and very few other sites in the UK, so on my way to watch Cove Rangers beat Forres Mechanics in a Highland League match, my football ground-hopping friend and I went to look for it.
The sea cave is cut-off by high tide and it was nearly high tide when we got there. Scrambling over wettish rocks I found the cave which has four different ferns in it just to make life complicated. There isn't very much of this plant, which looks quite like Cystoperis fragilis (Brittle Bladder-fern), except that the pinnae are crowded and overlap. The other distinguishing feature is supposed to be that the spores are minutely warted but in C. fragilis there is a spine. There weren't any spines on the spores that I could see but the absence of a characteristic can never be used as postive proof of identification. Stace is unconvinced by this separation of species and suggests that this plant represents a chance combination of characters rather than a different taxon.
When I first saw it many years ago that was my reaction - it's just a funny looking Brittle Bladder fern growing in the wrong place. But at present it is supposed to be a rare and different species from C. fragilis so who am I to argue?
So what did my ground-hopping friend think of this unique experience to see one of the UK's rarest plants?
"Rubbish".
Stace might well agree.
Sea Cave south of Aberdeen, 20th August 2005
Added on August 21st 2005, updated 10th December 2008, updated 21st March 2010