Sunday, 11 September 2016

Botanical find of the year? Probably!

Oonagh, Janice, Hammy & Jan start
exploring the wood
Image: R. Hodd
You may already have seen the star find from the recent Cork Recording Event on the Bulletin Board on the BSBI News page. One of the recording groups, led by Irish botanist/bryologist Rory Hodd of Rough Crew fame, found not only the gametophyte but also the sporophyte of the near-legendary Killarney Fern. The location of their find is being kept top secret, for reasons that are explained in this account by Rory: 

"Killarney fern (Trichomanes speciosum) has always had a mythical status amongst Irish and British botanists, being a member of a mainly tropical genus restricted to a small handful of humid sites mainly in the southwest of Ireland and Britain, as well as having a sad history of over-collecting by Victorian botanists, thanks to its delicate ethereal beauty. 

Sprorophyte of Killarney Fern
Image: R. Hodd
"Indeed, it is so rare and threatened in Europe as a whole that it is strictly protected under EU law and details of the location of any sites are top secret and preciously guarded. As the name suggests, its classical location is in the Killarney area of Kerry, where it was once abundant, but the Victorian fern craze led to its demise in all but the most inaccessible locations, with reports of the time speaking of locals selling the fern by the wheel-barrowful. 

"Like all ferns, Killarney fern has independent gametophyte and sporophyte generations, although the gametophyte generation, which grows as a green velvet mat in dark humid caves and under boulders, often a long distance from the nearest sporophyte colony, was not recognised until 1991. Since then, this generation has been found to be relatively widespread and abundant in places, but still rare in the scheme of things, although not anywhere near as rare as the showy fronds of the sporophyte generation.

"In this context, discovering a new colony of gametophyte is always nice, but to discover a new sporophyte colony is a very infrequent and exciting event. So, when West Cork based flute-maker and wildlife enthusiast Hammy Hamilton mentioned to me during last week’s Cork Recording Event that he knew of a fantastic wood, previously unvisited by botanists, in a steep valley with a stream running through it, that he felt might be home to Killarney fern, I was immediately intrigued and we decided to take a small group there on the final day of the Recording Event.  

Gametophyte of Killarney Fern
Image: R. Hodd
"A pleasant stroll through an upland valley opened up a vista of a rocky undulating hillside clothed in native trees, and we plunged down through dense Molinia tussocks, covering deep rocky holes, to enter lush woodland alongside a small tumbling stream. 

"An abundance of Kidney Saxifrage (Saxifraga hirsuta) and the common (in these parts) St. Patrick’s Cabbage (S. spathularis) as well as the hybrid between them (S. x polita) indicated the constant moist humid shady conditions present. Upon spying the steep sided rocky cleft from which the stream issued forth, my instincts told me that Killarney fern must be present, at least in its gametophyte form.

Tunbridge filmy-fern
Image: R. Hodd
"We scrambled into the ravine, and soon spotted a small cave formed by a boulder beside the stream. I poked my head under the boulder and turned on my head torch to confirm what I already guessed, the walls were covered by a luxuriant glowing fuzz of Killarney fern gametophyte. Already satisfied, we continued to follow the stream upwards through the rocky woodland, quickly finding an abundance of our two other filmy fern species, Tunbridge filmy-fern (Hymenophyllum tunbridgense) and Wilson’s filmy-fern (H. wilsonii), as well as the beautiful rare oceanic tropical liverwort Dumortiera hirsuta, and more Killarney fern gametophyte in every suitable crevice. 

"As we approached a jumble of boulders below a rockface, through which the stream flowed, I remarked, only partly in jest, that there’d definitely be sporophyte there, and I could scarcely believe my eyes when I looked down and there was a perfect mature frond of Killarney fern sticking out from between two boulders. 

Oonagh admiring Wilson's filmy-fern
Image: R. Hodd
"The excited and elated team quickly converged on the spot to pay their respects, and a quick search revealed a further 20 fronds hiding in the crevice below. After swearing an oath not to reveal the location to anyone, we clambered out of the woods and into the daylight, privileged to be the first botanists to set eyes on this population of such a rare and captivating plant, adding to the very short list of known sites for the sporophyte in Ireland or Britain. It's days like that that make botanising off the beaten track so rewarding and worthwhile".

Many thanks to Rory for telling us about this amazing find. It was a privilege to meet the man himself at this weekend's AGM of the British Bryological Society and congratulate him on his sharp eyes and skill as an ecologist. Thanks also to Hammy Hamilton - you can't beat local knowledge, especially when paired with an understanding of the ecology of the plant you're looking for, so you know where to hunt for it. 

Botanical find of the year? It will be hard to top both generations of Killarney Fern, but Ghost Orchid hunters may yet come up trumps ;-)