Nail Fungus (Poronia punctata)
This rare ascomycete fungus, found on the dung of ponies and horses, takes its vernacular name from the resemblance of the fruiting bodies to broad-headed nails. P. punctata is now very scarce in Britain and Ireland and confined to sites where ponies feed exclusively on rough pastures and heathland. Herbicides, plant pesticides and synthetic chemicals used in the worming of horses have been blamed for the demise of P. punctata across much of Europe. The spores are ingested by livestock whilst grazing and are passed out with their dung. The spores germinate and form the mycelium of the fungus, eventually producing the visible fruiting bodies after the dung has had time to weather.
This species was included as Endangered on the Red Data List prepared by Bruce Ing (1992); and as Near Threatened on the Red Data List produced by Shelley Evans et al. (2006). P. punctata is a UK Biodiversity Action Plan (BAP) species.
My thanks to good friends Jim and Dawn Langiewicz for their recent help in locating this species and to Nick Aplin, Sussex county recorder for ascomycetes, for the above photomicrographs. These show the ascus apex staining blue in the top picture and a germ slit on the ascospore in the top right in the bottom picture.
O’Reilly, P. (2016). Fascinated by Fungi – exploring the majesty and mystery, facts and fantasy of the quirkiest kingdom on earth. Llandysul: First Nature, p. 372, 407.
Sterry, P. and Hughes. B. (2009). Collins Complete Guide to British Mushrooms and Toadstools. London: HarperCollins, p. 344, figs. p. 344-345.