in temperate North America, from Nova Scotia, Ontario, and Minnesota south to Florida and Louisiana. Generally occupying moist and shaded areas, like the nutrient-rich slopes along streams, the plants produce three- to five-parted leaves from a rounded corm. The corms, when dried or boiled, served as an
emergency foodstuff for Native Americans and early settlers, giving the plant the common name "Indian turnip." In addition, a salve for treating ringworm and
snakebite was made by mixing me raw corm with lard. (WARNING: Raw corms contain large amounts of calcium oxalate crystals which, if ingested, cause
intense pain and irritation of the throat's mucosal membranes.)
In Alabama, jack-in-the-pulpit leaves and inflorescences emerge from the forest floor litter in April. An inflorescence consists of a slender stalk (spadix) surrounded by a green- or purple-striped sheath (spathe); the latter droops protectively over the top of the entire structure, like the canopy of an old-fashioned pulpit. Borne on the lower portion of the spadix are fifty or so highly reduced flowers--all male, all female, or (occasionally) both. Upon release, the light pink pollen collects in the bottom of the cup formed by the spathe; tiny insects called thrips (Heterothrips arisaemae) drench themselves in pollen, carrying it to a neighboring plant. The red berries ripen in August and are consumed by woodland creatures such as box turtles, and the seeds are disseminated with their droppings.
Although posing as simple herbs, jacks actually follow a complex sexual scenario--the size-advantage model--similar to some advanced animals. According to this model, an individual will "choose" to be either male or female depending on the reproductive advantage to be gained; the amount of stored nutrients is a major determining factor in this choice. Large, healthy individuals, capable of sustaining the offspring, will be female; smaller and less healthy ones, required only to produce gametes, will be male; and marginal ones will "choose" not to reproduce at all, but concentrate instead on building up reserves for the next season.
In jacks, this all makes for a confusing (but predictable) situation known as sequential hermaphroditism. From one year to the next, an individual plant may change from asexual to male or female, from male to asexual or female, or from female to asexual or male. Size, rather than history or age, is the best predictor of sexual state, since a plant's size is a measure of its photosynthetic health--stored in the corm as starch--during the preceding year. Robust plants can "afford" to be female and support two leaves; males have only one leaf but are larger than asexual plants. The females of a population usually develop on the most favorable sites, with males and asexuals on the harsher, less fertile edges.
So the microenvironment, operating through the modification of endogenous hormone levels, must be considered as the ultimate determiner of gender in jacks. This environmental monitoring system ensures that the burden of fruit production is borne by the healthiest individuals, increasing the likelihood that genetic materials will be transmitted to the next generation.
Jacks-in-the-pulpit, then, are "jacks" only when living less than ideal lives. As in other species, the most vigorous members of a population-and the ones bearing most of the reproductive costs-are the "jills."