Field identification of dicotyledons: A punched card system for the identification of families

Abstract

A punched card key for use in the identification of dicotyledons to a family level is described. It has advantages over the ordinary dichotomous key in that it allows early use of the most conspicuous or most selective characters of an unknown plant. It also facilitates the identification of incomplete material.

The key is based on Hutchinson's (1926) descriptions. Cards for his 264 families have been prepared.

A sample card shows the characters used and the method of clipping, and an illustration of the card set shows the distribution of various characters between families.