Jack-in-the-Pulpit (Arisaema triphyllum)
Jim Lakin MD, Master Gardener
Jack-in-the-Pulpit is a shade requiring native plant best grown in rich, moist woods or marshes. Read about this unique and fascinating long-lived perennial here.
It takes a special kind of plant to survive near our marsh. The ground ranges from damp to soggy, the shade is at best partial but mostly deep once you step a foot or two into the surrounding woods. Yet it is in this challenging environment that Jack in the Pulpit is most content. This unusual but long-lived native perennial is found in moist woodlands throughout most of the eastern half of the United States. It is prevalent throughout Minnesota and most of the Upper Midwest, hardy up through Zone 3.
The flower is 3 to 4 inches tall and about 2 inches across. It is made up of a 2- to 3-inch-long club (the “Jack”, or spadix) sitting in a tubular base with a hood (the “pulpit”, or spathe). The spadix is light to reddish green. The spathe is light to purplish green and often dotted with white or purplish stripes. Plants are either male or female but you can’t tell without peering into the “pulpit”. It is there that either the staminate (female) or pistillate (male) organs are to be found. Speaking of gender, Jack in the Pulpit is rather fluid in that department. A given plant can change sex from year to year. Apparently, this is a function of how successful they were or were not in pollinating during the previous season. Once the plant decides if he/she is to be a boy or girl for the season its structure differentiates accordingly.
Males tend to be smaller than females. They sprout from an underground corm which can send out runners producing additional plants. Consequently, Jack-in-the-Pulpits are usually found in colonies with a tall female plant surrounded by smaller male plants. The male plant has a hole in the bottom of its spathe (“pulpit”) which provides an easy exit for pollinating insects, usually small flies or gnats. In contrast, females have no such exit in their spathe, forcing a would-be pollinator to squirm around a bit to get out. This increases the likelihood of pollen being deposited on the staminate structures within the spathe. Pretty clever interior design!
Jack in the Pulpit can be grown from seed but it takes four to five years before the plant flowers. So, if you are thinking of planting some, you might consider buying a corm instead of seed. Once mature, the female plant produces flowers in late spring to early summer. When fertilized smooth green berries are produced. In late summer they ripen to a deep red as the leaves wither. These berries are about a quarter inch in diameter appearing in ovoid shaped clusters which can be up to 2 inches long. Each berry contains one to seven small seeds. These prove tempting to many woodland birds, including wild turkeys, who eat the ripe berries and excrete the seeds.
So, if you have a moist shaded spot in your garden and are looking for a suitable native perennial, the unusual but showy Jack in the Pulpit may just be your guy.
Photo credits: Flickr.com (1, 2)