Published online by Cambridge University Press: 31 May 2012
Most of the species of plants in the arum family, Araceae, have their flowers arranged on a central spadix which is surrounded by an enveloping spathe. These floral mechanisms have been classified by Müller (1883). The simplest type, represented by the water-arum, Calla palustris, has the spadix fully exposed and the spathe held back from it. Secondly, there is the type in which the spadix is surrounded by the spathe and is only partly visible through the opening of the spathe, as represented by the skunk cabbage, Symplocarpus foetidus. Thirdly, there is the most elaborate arrangement, represented by the cuckoo pint, Arum maculatum. In this type the spathe surrounds the spadix and is constricted a short distance above its base to form a chamber surrounding the flowers which are concentrated at the base of the spadix. Thus there is formed a “pitfall mechanism” or “kettle trap” which entraps insects that have entered the spathe and ensures the pollination of the flowers by the insects (McLean and Ivimey-Cook, 1956; Müller, 1883).