EEB337H1 - Families of Vascular Plants

Multiple-entry keys (polyclaves)

Polyclaves permit the user to employ whatever data are available, in any order (hence multiple-entry), to narrow down the list of possible identifications for an unknown specimen. Although edge-punched cards have been used in the past, polyclaves are now implemented most effectively as computer programs. Given the huge volume of data available to be used with such programs, and the vast array of other possible uses of these same data, development of a comprehensive system for organizing these data has been critical. Currently, the internationally accepted standard is the DELTA system.


The DELTA format and identification programs that use it

DELTA logoThe DELTA (DEscriptive Language for TAxonomy) system provides a means by which to code taxonomic data for a host of uses, including multiple entry keys. A particular strength of this format, especially in its identification applications, is the ability to incorporate images both of characters and their states, and of the taxa for which these data are available. The following four programs implement multiple-entry keys that take advantage of the DELTA format:

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PollyClave logo, and how to use it with DELTA databases

PollyClave logo was developed at the University of Toronto and the ROM. It was designed to emulate INTKEY while running on a WWW server. Users of browsers like Netscape Navigator, Internet Explorer, and others can thus use it to access online DELTA databases and make interactive identifications.

PollyClave will allow students in EEB337H to use and examine taxonomic databases related to the Ontario flora (as well as other sets of taxa). Click here, or on the PollyClave logo, to go to the PollyClave home page where you can access the help screens that explain the datasets available and how to use PollyClave most effectively with them.

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| What are plant families? | How do we distinguish them? | How and why do we study them? | Selected vascular plant families of Ontario | Reading List | Course outline |

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Please send your comments to tim.dickinson@utoronto.ca; last updated 29-Oct-2009