Flowering Plant Family Identification


This WWW form is an implementation of the Hansen and Rahn punched card system for flowering plant family identification (Hansen, B., and K. Rahn.  1969.  Determination of angiosperm families by means of a punched-card system.  Dansk Botanisk Arkiv 26:1-46 + 172 punched cards.). It is comprehensive to enable world wide flowering plant identification. In the original form, each card of the deck is labeled as one character (actually, character state, such as “Leaves Opposite”), there being 172 cards in the deck. On each card there are 411 numbered circles, each corresponding to a family of flowering plants. If the character listed on the card was known to be present in at least one member of a family, that family number-circle was punched open.

The process of identification requires sorting through the deck of cards, pulling out those that present characters observed in the specimen that is being identified, putting this set of cards together in a stack, holding the stack of cards up to a light source, and seeing which family numbers were punched through on all the cards in the stack. If a suitably large number of character cards are selected, only a single family number will be punched on all the cards, and the identification will have been made. More typically, a number of families will be identified as possible.

The punch card system is a process of elimination. Selecting a card excludes certain families because their numbers are not punched on that card. Because a family number is punched if ANY member of the family has that feature, only those families that the specimen could not possibly be are determined by each character card selection. If a mistake is made in selecting a card because of misinterpretation of the character or in examining the specimen, misidentification might occur.

Electronic forms of this identification system were developed by Ray Phillips at the University of Oklahoma and at Colby College. Versions were developed for UNIX systems and enhanced capabilities included in a Macintosh application (MagnolioFam). This version uses the same data in a Web form with the same search algorithms as the earlier ones and functionally equivalent to the original card system.

A Windows application, MEKA – Multiple-Entry Key Algorithm , using these data has been developed by Thomas Duncan and Christopher A. Meacham at the University of California, Berkeley.

This system is amenable for the identification of other taxa.

Comments and suggestions should be directed to Ray Phillips, Director of Information Technology Services and Assistant Prof. of Biology, Colby College, Waterville, ME 04901.

Return to the Key