Into the Woods: The Private Life of Jack-in-the-Pulpit

By Ted Watt Gazette Contributing Writer

One of my favorite spring wildflowers is the jack-in-the-pulpit, a common native perennial in deciduous woodlands throughout our area. Although it’s not showy, it has some of the most interesting adaptations of any plant you’re likely to come across while on a spring woods walk.

As a perennial, one of its jobs is to store food to survive the winter as a bulb (corm), so it can send up its sprout the following spring. During its fall and winter dormant period jack-in-the-pulpit is vulnerable to predators seeking the starches stored in the bulb. However, it protects itself very effectively, which a friend and I learned firsthand.

We were exploring a floodplain forest along the Connecticut River. We found a nice patch of jacks and decided to test out what we had heard: that the bulbs were painful if eaten. My friend pulled a bulb, sliced it open and carefully touched her tongue to the bulb a couple of times and waited. Nothing. She then took a big hearty lick and a few minutes later her mouth began to burn.

The bulb contains calcium oxalate crystals that pierce the tongue and soft tissue of the mouth. Luckily we hadn’t eaten them!

If you find a jack in flower, take a moment to look closer. Not beautiful in the traditional sense of bright colors and sweet scents, the odd-shaped brown-green flower shares the purpose of all flowers—to produce pollen and ovules and fertilize its seeds.

Each jack flower is either male or female. You can tell the sex of the particular specimen you’re looking at by gently pulling the sides of the pulpit apart and looking around the base of the jack. There you should see either tiny, shiny, green seeds (in the female) or tiny, cream-colored stamens with pollen (male).

Here’s the intriguing part: If you come back to the same plant next spring you’ll have to check all over again because individual plants can change their sex from year to year. The sex of the jack is determined environmentally, not genetically. If a plant has a good year and stores a significant amount of food, the following season it will bloom as a female. If it has a bad year, the next season it will bloom as a male.

Females are bigger and more robust than males because they have to support the growing and ripening seeds. (All males have to do is produce the pollen dust, a drastically smaller expenditure of energy.)

Jacks are pollinated by fungus gnats, which find their way under the overlapping pulpit and down the flowers’ large opening to the pollen and ovules at the base. These gnats are weak flyers and the task of flying up and out the top of the pulpit is difficult for them, so the plant accommodates by providing them with an escape hatch.

To find the gnats’ exit, look for a tiny opening less than 1/16th of an inch at the base of the pulpit, where two layers of tissue overlap. If the plant blooms as a male, the opening allows the weak flyers to escape and carry pollen to the next flower. In female flowers the opening is absent, since the plant has no need for the gnat to take anything to another flower.

During the summer, when they grow and mature, jacks stay green like most fruits. When they ripen in September, they turn a brilliant scarlet. Sending this signal that its fruits are ripe attracts birds. When a bird eats the fruit, it digests the soft parts of the fruit and excretes the seed—usually far from the parent plant, often in a new suitable habitat.

The life cycle of the jack-in-the-pulpit is beautifully complex, relying on other species for pollination, seed dissemination and, ultimately, survival. The next time you see one of these diminutive gems, consider the web of life that a single plant can represent.

Ted Watt is an environmental educator/naturalist at the Hitchcock Center for the Environment.

Earth Matters, written by staff and associates of the Hitchcock Center for the Environment at 525 South Pleasant St., Amherst, appears every other week. For more information, call 413-256-6006, or write to us.

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