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NEWS RELEASE No: 1600619 JULY 2013

Smutty naked ladies - a new fungus find at Westonbirt

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smutty naked lady fungus

A rare, endangered, species of fungus has been recorded for the first time in Gloucestershire, at the Forestry Commission’s National Arboretum at Westonbirt.

The sooty-black smut fungus Urocystis colchici only infects the leaves of Naked Ladies (Colchicum autumnale) also known as Meadow Saffron or Autumn Crocus (although it is not a true crocus).

The smut-fungus is so called because its spores are a sooty-black colour. These are formed in blister-like sores (sori) on the leaves, each producing hundreds of thousands of minute powdery brown-black spores.

The host plant has this interesting common name because it flowers in the autumn months after the spring leaves have rotted away, thus the flowering plant appears naked.

The fungus was found on a few leaves of a single plant, after an extensive search by Dave Shorten of the Cotswold Fungus Group, who commented:

“It is very exciting to have made a sighting of this extremely rare fungus at Westonbirt Arboretum. The Forestry Commission’s management of the landscape has provided the ideal conditions for the species to survive.”

Urocystis colchici is an extremely rare and legally protected species of fungus. Natural England describes it as a species of “principal conservation importance” in England because of its rarity and potentially threatened habitat.

The British Mycological Society count the fungus as a Critically Endangered species, cited as such on the IUCN Red List of Threatened Species. It also appears on the national Biodiversity Action Plan as a fungus species for conservation.

Very little is known about the fungus and in England it has only been seen twice in the past decade, in Herefordshire and Oxfordshire.

This fungus is a legally protected species and should not be picked, however, if you come across it at Westonbirt Arboretum, please note the identification number of the nearest tree (top-left corner of the tree label) and provide this along with a description of how to find it from there to


Images attached: The smut fungus Urocystis colchici on the leaves of Naked Ladies (Colchicum autumnale). Credit Dave Shorten.

1. Westonbirt, The National Arboretum is managed by the Forestry Commission and is renowned worldwide for its tree and shrub collection. Home to five national collections, the arboretum covers 243 hectares (600 acres) and contains 16,000 labelled specimens. Visitor numbers are 350,000 a year, with a membership of over 28,000. Westonbirt Arboretum was established in the 1850s by wealthy landowner Robert Holford and later developed by his son George Holford. Unlike many arboretums, Westonbirt is laid out according to aesthetic appeal rather than scientific or geographical criteria. Visit

2. The Forestry Commission is the government department responsible for protecting, expanding and promoting the sustainable management of woods and forests and increasing their value to society and the environment.  Further information can be found at

3. The Friends of Westonbirt Arboretum was formed in 1985. The charity’s objects are to support The National Arboretum in promoting public understanding of the crucial role of trees to the environment and society. It is funded by membership receipts from over 28,000 members, other fundraising, and the use of the Great Oak Hall for events and activities. The Friends of Westonbirt Arboretum is a registered charity (no. 293190). More information at  

4. The Westonbirt Project will make a big difference to everybody who comes to the arboretum. The project will mean a better welcome, a better visit and a better understanding of the heritage and importance of this world class tree collection. More information can be found at

Useful links:

British Mycological Society:


Gina Mills, Communications Manager, Westonbirt, The National Arboretum, on 01666 881 231 or email