Lost & Found: Chrysomyxa pirolata; a rust fungus on Wintergreen

Tony Carter, Chrysomyxa pirolata

With financial support from the Esmée Fairbairn Foundation, Kew has embarked on the Lost & Found Fungi Project, a five-year UK fungal research programme in partnership with the volunteer science community. With support from Kew, local fungus recording groups are carrying out surveys and monitoring exercises for a set of 100 species that are currently assumed to be rare, to establish whether they are still extant in the UK and, if so, whether their distributions are larger or smaller than are known at present and whether they are threatened.

One such species is Chrysomyxa pirolata, a rust fungus that grows on Pyrola rotundifolia subsp. maritima (Wintergreen). This plant grows on the Sefton Cost and the fungus was last recorded on the Ainsdale & Birkdale Sandhills Reserve. It is listed as an endangered conservation species.

So off I went to Ainsdale on a very blustery day. First find your Wintergreen. Not being much of a botanist, I received some good advice on identification and where to find it from a colleague at the Liverpool Botanical Society, and the Head Ranger who also advised it was not in flower.

I started in the Birkdale side of the reserve. I was in luck. It had started to flower. I found four large patches of plants. The rust grows on the underside of the leaf so I had to turn each leaf to see if it was present. After two hours of searching there was no sign of any rust.

So I went south to the Ainsdale side of the reserve, along the marked track round a large dry slack. I came across a very large patch of Wintergreen on a hillock. As I stood pondering the mass of leaves to be examined I had a bit of luck. There was a strong gust of wind. Some of the leaves flapped and i caught a glimpse of orange. I pounced. There it was - Chrysomyxa  pirolata

I could only find a small patch of rust but some was seen on the top side of one of the leaves and a few on the petioles, a fact I had not seen mentioned in any of the literature.

I took a few samples and having satisfied myself, after microscopic examination, that my identification was correct, I dried and pressed it. I sent it to Kew Herbarium where it was confirmed by Dr. Martyn Ainsworth. It was he who had previously found this species, at Ainsdale, very near to my find.

For more information see http://fungi.myspecies.info/content/lost-found-fungi-project