Figure 1. The life cycle of skunk cabbage (Symplocarpus renifolius).

S. renifolius is a polycarpic plant that flowers after several years of vegetative growth. In early spring, the flowers begin producing heat when they bloom and terminate heat production when the pollen is released from the anthers. At the end of spring, leaf development is initiated at floral senescence, and environmental conditions determine whether or not flowers will bloom in the following year. In summer, if pollination is successful, the flower becomes a fruit, which contains many seeds. (a) Seeds, (b) seedlings, (c) immature-stage flowers (pre-thermogenic stage), (d) female-stage flowers (thermogenic stage), (e) male-stage flowers (post-thermogenic stage), (f) developed leaves, and (g) fruits. The thermal image of the right panel in (d) was taken using an FLIR SC 620 thermal imager (FLIR SYSTEMS).