A bit of a mystery today: a fern that I saw last month at Mount Usher. It is a mystery because I am not sure what it is! I am fairly sure it is a pyrrosia fern, usually called tongue ferns because of the thick, leathery fronds. Most also have a felted underside. This one was growing in shade at the top of a well-drained bank, running around with long rhizomes and simple, upright fronds about 8-10cm apart.
I was fairly certain it was Pyrrosia lingua, a species from east Asia but then I noticed that some of the fronds were lobed or ‘fingered’ and that threw me. So now I am not sure at all! I am still convinced the genus is right though and the way it has found a tree and started romping up it sort of confirms that – unless you know different.