Collected on May 19, 2006, this specimen was found by Loree Speedy in a stream valley near the Mill Run Reservoir in Fayette County, Pennsylvania. This charismatic species (Arisaema triphyllum) is known as jack-in-the-pulpit and is native to forests of the eastern United States.
Its common name comes from its flowering structure—a distinctive hooded structure (spathe) that looks like a pulpit and the flowers (spadix) that resemble “Jack,” the minister standing within. This flower structure is shared among members of the arum family (Araceae; members often called aroids), which includes the popular houseplants known as peace lilies.
The natural history of jack-in-the-pulpits is fascinating. For starters, individual plants can be male or female, and the gender can switch from year to year! This species has intrigued botanists for decades and has been used as a study system to understand the ecology and evolution of plant sex expression. Larger plants tend to have female flowers, but the exact size is dependent on environmental conditions and genetics of a given population. Jack-in-the-pulpit has calcium oxalate in its leaves that can irritate skin and is poisonous to ingest.
It is generally avoided by deer. However, recent research from the lab of Susan Kalisz—a research associate at the museum—has shown that deer overabundance negatively affects the growth of this species. While it is rarely eaten by deer, they affect other environmental conditions, such as light levels and soil conditions.
Botanists at Carnegie Museum of Natural History share pieces of the herbarium’s historical hidden collection on the dates they were discovered or collected. Check back for more!
