Lichens

• British Lichen Society
• UK Lichens by Mike Sutcliffe
• Irish Lichens - A photographic guide
• Lichenland - Fun with lichens from Oregon State University
• The Lichen Herbarium, University of Oslo
• University of Oslo - Botanical Museum - Lichen Herbarium Photo Gallery
• Leif & Anita Stridvall - Lichen Gallery (Swedish lichens)

General

• Northern Ireland Environment Agency
• National Museums Northern Ireland
• Biodiversity
• National Botanic Gardens, Glasnevin
• Department of Environment, Heritage and Local Government
• National Parks & Wildlife Service
• National Biodiversity Data Centre