Jack-In-The-Pulpit: Secrets Exposed



May is the season when observant woods-walkers and trail hikers are rewarded with visual treats of all sizes, shapes and colors. Fawns lay motionless in dappled sunlight. Migrating Warblers sing from shrubs, morels emerge and Osprey soar high overhead. In the rain-soaked woodlands of our larger Oakland County Parks, Jack-in-the-Pulpit, perhaps the strangest perennial wildflower of all, has emerged from winter dormancy. Jack has a secret that breaks the rules of botany. Jack is sometimes Jill, and Jill may switch back to being Jack. Confused? Here’s the rest of this flowery tale of Oakland County’s mysterious forest floor hermaphroditeArisaema triphyllum.


“Jack” is the spongy cylindrical structure that can be seen under the multi-colored striped hood of the plant. The “pulpit” is the curved hood. That ensemble spawned the name Jack-in-the-Pulpit because it reminded some of a minister (Jack) preaching from an old-fashioned church pulpit. Botanically speaking, Jack is a spadix and the pulpit is the spathe. The actual flowers are very tiny and are located out of sight, at the base of the spadix and inside the spathe. If you were to carefully peek deep inside and see a tiny cluster of berries, the plant is female. If only thread-like brown anthers appear (the anther is the small structure found at the end of the stamen that is responsible for producing pollen), the plant is male. It’s interesting to note that if you were to mark the location of the plant and check back the next year, the sex may have changed.

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The United State Department of Agriculture explains, “Plants will be female when they reach a sufficient size to provide stored resources to support flower and fruit production but will revert back to being male, or nonflowering if stored resources are depleted. Plant sex may also fluctuate with environmental resources like moisture and nutrients.” The bottom line is Jack-in-the-Pulpit has been and remains one of the most widely studied of the few species of sex changing plants on our planet. Studies show that size matters as well. The sex of the plant is determined by the size of last year’s buried root structure, known as a corm. Small corms produce males and large corms create females. Fortunately, there is an easier and less invasive way than digging up corms or peeking deep down into the spathe to discover if you have found Jack-in-the-Pulpit or Jill-in-the-Pulpit. Here’s how!

In early May, as you hike the trails and explore the woodlands of Oakland County, you’ll notice the underground corm of Jack-in-the Pulpit shoots up a green spear-like structure that unfolds and reveals the sex to those that read the coded message. Every Jack-in-the-Pulpit has either one or two leaves. One leaf, it’s Jack. Two leaves, meet Jill. Happy hiking!

Text and photos by Jonathan Schechter, Nature Education Writer for Oakland County Parks. schechterj@oakgov.com

Visit Destination Oakland for details on all 13 Oakland County Parks.


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