The MEKA Home Page

New Developments:

MEKA development has returned to the Herbaria. Thomas J. Rosatti has developed many keys to California plants, which are available through the Jepson Flora Project. As of February 2005, a new Windows version of MEKA-Edit is available, which includes a conversion function that can convert any MEKA key to the SLIKS format developed by Gerald Guala for Web-based identification. Please visit for more information about SLIKS.

Support for continued development of MEKA from the Lawrence J. Heckard Fund of the Jepson Herbarium is gratefully acknowledged.

Chris Meacham
University and Jepson Herbaria
University of California, Berkeley
22 August 2005

Many thanks!

Prof. Knud Ib Christensen of the Botanic Garden of the University of Copenhagen has performed a great service in developing a web document, Introduction to using MEKA, showing the operations of of the Windows version of MEKA in detail. Of particular importance is his description of the format of the index file, which is not described in the MEKA documentation. He has also made available his key to Old World Crataegus, and he has converted his MEKA keys to SLIKS keys using MEKA-Edit.

MEKA (pronounced "mecca") is an interactive Multiple-Entry Key Algorithm to enable rapid identification of biological specimens. Earlier versions of the program used a command-line interface. The version offered here is the first version developed to run under Windows. MEKA is controlled by mouse clicks; no text is entered. This approach allows very rapid access to program functions.

The user picks character states that are present in the specimen from a list of possibilities. As the character states are scored by picking them, MEKA eliminates taxa that no longer match the list of scored character states. Different windows display different aspects of the underlying data base. As the identification progresses the windows are updated automatically. An index screen makes it easy to find and score particular classes of character states. MEKA does not lead the user in a fixed stepwise progression through a series of questions. Instead, the user can perform identifications by scoring character states in any order. This makes it possible to identify specimens that are much more fragmentary than is possible with dichotomous keys.

If you want to try out MEKA, just download the self-extracting, self-installing Windows archive, MEKA31.EXE by clicking on this button:

Download MEKA for Windows Click Here to Download MEKA for Windows 1.2 megabytes

Please read the MEKA copyright notice.

When you execute MEKA31.EXE under Windows, the archive will expand to install MEKA for Windows, a documentation file, three different plant keys, and an uninstall program that will cleanly remove all the installed files when you wish.

Three keys to flowering plant groups are included in this self-extracting archive:

"WOODY" - Key to Wetland Woody Plants of North America by John T. Kartesz of the Biota of North America Program. This key is copyrighted by Dr. Kartesz and should not be distributed further without his permission. He may be reached by telephone at 919-967-6240. This is a draft version. Please report any inaccuracies to Dr. Kartesz. The Woody key was developed through funding provided by the U.S. Fish and Wildlife Service, National Wetlands Inventory. Please contact Porter B. Reed for further information.

"ANGIOFAM" - Key to Angiosperm (Flowering Plant) Families of the World by Bertel Hansen and Knud Rahn of the Botanical Museum and Library of the University of Copenhagen. The copyright for this key has been transferred to Christopher Meacham.

"TROPIFAM" - Key to Woody Plant Families of the Neotropics by Donald R. Simpson and David Janos of the Field Museum of Natural History, Chicago.

Here is an older, MS-DOS version of MEKA that some have asked for. The file is a self-extracting MS-DOS archive.

Download MEKA for MS-DOS Click Here to Download MEKA for MS-DOS 123 kilobytes

Related links:

Michael J. Dallwitz, developer of the DELTA system, has compiled a very useful list of programs for interactive identification.

David C. Hurd of Ukuleles by Kawika, Inc. has developed a MEKA key to ukuleles.

Christopher A. Meacham
University and Jepson Herbaria
University of California, Berkeley
1001 Valley Life Sciences Building
Berkeley, CA 94720-2465 USA

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