Lichen determination keys

A. "Traditional", articulated keys, taxonomical / geographical arrangement ( B. Interactive keys )
These keys can be downloaded and used with an internet browser to keep the link functions, or (many of them) printed and used like a traditional, printed key. Several keys are presented with the internet adaptation developed by Tom Hollowell (Smithsonian Institution, Washington), whose cooperation is gratefully acknowledged. For further lichenological web publications see Zschackia.

Last update 24 August 2012; information about further web keys and changed addresses will be much appreciated.

• Keys to the lichen genera of the Neotropics by H. Sipman, partially revised 2005
• Key to the lichen genera of the Guianas (tropical South America) by H. Sipman 1996
• Key to the foliicolous lichen genera of the World
• Key to the podetiate and pseudopodetiate lichens of highland Ecuador (genera Baeomyces, Cladia, Cladina, Cladonia, Dibaeis and Phyllobaeis)
• Key to lime-loving (calciphilous) lichens in eastern North America
• Synoptic key for some common NorthWestern USA lichens
• Illustrated key to British twig-inhabiting lichens 
• Terricolous lichens of Italy (pdf-file)
• Cladoniaceae of Chile
• Lichen genera of Iran
• Common Malesian Lichen genera

• Key to the foliicolous species of the genus Arthonia
• Key to Bacidia, Bacidina and Fellhanera of the Ozarks, USA (with descriptions, illustrations)
• Key to the tropical species of Buellia s.l. with 2-celled spores
• Keys to the Caliciales of Norway
• Keys to the genus Caloplaca, offered by Cliff Wetmore ("Gasparrinia", brown-black-fruited species, sideritis-group, sorediate/isidiate species)
• Key to Cladina and Cladonia on the Queen Charlotte Islands and neighboring areas
• Key to the genus Cladonia on La Reunion, by H. Sipman, 2011
• Key to the genus Cladonia in S.E. Brazil, by H. Sipman, 2013
• Key to the Cladoniaceae of the Guianas
• Key to the Cladoniaceae of Chile
• Key to the genus Erioderma on La Reunion by H. Sipman, 2011
• Key to Gomphillus in eastern North America
• Working keys to Graphidaceae of Costa Rica
• Working keys to Gyalideopsis worldwide
• Keys to sorediate, isidiate Heterodermia and to Heterodermia with podocarpa-type thallus, by Felix Schumm, PDF-files (in German)
• Key for the genus Hyperphyscia worldwide, by H. Sipman, updated 2013
• Revised key for the genus Hypotrachyna in Tropical America, by H. Sipman 1998
• Preliminary key to Lecanora species likely to occur in New England
• Revised key to the Megalosporaceae (genera Austroblastenia, Megaloblastenia and Megalospora)
• Compiled key to the species of the genus Mycomicrothelia worldwide.
• Key to Ophioparma in eastern North America
• Key to the Parmeliaceae of Macaronesia by Felix Schumm, PDF-file (in German)
• Key to the genus Parmelia in Great Britain and Ireland (illustrated version offered by British Lichen Society on CD)
• Key to the genus Parmelia s. str. in eastern North America
• MASON HALE's key for the genus Parmotrema, revised edition: key to wide-lobed parmelioid species occurring in Tropical America (genera Canomaculina, Parmotrema, Rimelia)
• Compiled identification key to the genus Pertusaria and some confusible taxa in Europe and the Mediterranean
• Preliminary world-wide key to the genus Pertusaria by A.W. Archer and J.A. Elix
• Revised key for the genus Pertusaria in Australia by Alan W. Archer 2012
• Key to the Australian Physciaceae, by J. A. Elix, 2011
• Key to the foliicolous species of the genus Porina, by Robert Lücking
• Key to the genus Porina on La Reunion by P. van den Boom 2011
• Key to Protoblastenia of the Ozarks, USA (with descriptions, illustrations)
• Key to the genus Pyrenula on La Reunion by P. van den Boom 2011
• Revised key for the genus Relicina worldwide by J. Elix and H. Sipman 1998
• Key for the genus Stereocaulon in Tropical America by H. Sipman 2002
• Key for the genus Usnea in Europe by T. Randlane, T. Tõrra, T. & A. Saag 2008, 2009

A geographical arrangement of available keys is available in the world checklist website. Select the desired country and click the button for keys.

Archived versions of these keys can be found at http://www.toyen.uio.no/botanisk/lav/LichenKey/.

B. Interactive keys.
These keys are based on a character set in a database and can be used only with a computer. They allow access with the users' own selection of characters.
For the latest, updated information see the LIAS site.
Available subsets from the LIAS project:

• Lichen Genera of Germany - BETA version - 96-07-22 - by G. Rambold & D. Triebel, This subset includes the (partly incomplete) data of 270 lichen genera.
• Genera with Foliicolous Taxa - BETA version - 96-11-22 - by G. Rambold & D. Triebel. (most data sets revised by R. Lücking). This subset includes the (partly incomplete) data of more than 80 lichen genera.
• Lichenologists involved in flora projects may obtain as well other subsets of the generic key right now.
• For the following genera subsets for species determination are available, prepared in cooperation with specialists: Arthonia (red-fruited), Biatora (Europe), Bunodophoron, Cladonia p.p., Diploschistes, Epigloea, Lecanora (key to 193 species of Lecanora s.str.), Lecideaceae (Europe), Megalospora, Miriquidica, Phaeophyscia, Rimularia, Tephromela, Vulpicida.
• LIAS-light: trimmed for the identification of (mainly) European lichen species; datasets for Germany and Great Britain are almost complete now; shortcut.

Further available:

• Interactive key to calicioid lichens and fungi of the Nordic countries /font>