Illinois Natural History Survey - University of Illinois

Compass Plant

 

Susan Post

 

Look at this vigorous plant that lifts its head from the meadow,

See how its leaves are turned to the north, as true as the magnet;

This is the compass flower. . .

(Henry Wadsworth Longfellow, Evangeline)

compass1.jpg

Compass plant is the common name of Silphium laciniatum, a member of the daisy family. Once common in mesic and drier prairies, today it is often found along roadsides and slightly disturbed sites from Michigan and Indiana, south to Alabama, west to Texas, and north to North Dakota. In 1777, William Bartram, an early botanist and traveler described the plant as, “the most conspicuous both for its beauty and novelty . . . The flower stem, which is eight or ten feet in length, terminates upwards with a long heavy spike of large golden yellow flowers.”

Compass plant is one of the largest-leaved plants of the prairie. It has huge basal leaves and a 3- to
8-foot flower stalk. On top of the hairy stalk are several alternate flower heads, each 2.5 to 4.5 inches wide with many yellow petal-like ray flowers surrounding a yellow center with disk flowers. The basal leaves are broadly triangular in general outline, and can be over 1 foot long and deeply divided into a series of narrow segments. The plant’s species name, laciniatum, is Latin for deeply cut or lacerated and refers to the basal leaves, which resemble a masterpiece worthy of Edward Scissorhands. The basal leaves of the compass plant align themselves in a north-south orientation; this allows the broad leaves to have maximum exposure to the morning and evening sun and minimal exposure to the hot drying noon sun. During a 90OF day, put your hands on the sides of the leaves, they are cool to the touch.

The plant blooms from June to September and usually flowers before big bluestem or Indian grass have reached their mature sizes, making the plant an unmistakable prairie landmark. Compass plant or polar plant (it’s other common name) was a plant many pioneer travelers used to find their way across the prairies. A clan of Osage Native Americans, who called themselves Walkers-in-the-Mist, used the tall compass plants to plot their routes across fog-bound prairies. Early wagon train scouts marked trails for their followers by tying flags to the flower’s stalks.

The plant’s root is equally impressive, attaining a depth of 10 to 15 feet. This enables it to weather prairie droughts and survive prairie burns. Left undisturbed, compass plant can attain a height of 6 to 8 feet every year, die back, and begin the growth cycle again, all due to its incredible root system.

Compass plant is one of 14 species of the genus Silphium to be found in the eastern United States. Members of this genus are tall and sturdy and have sunflowerlike blossoms. Silphium is the ancient name of a resinous plant, and plants of this genus have a pine-scented resinous sap. William Bartram also described the stems of compass plant when split, noting they “exude a resinous substance which the sun and air harden in semi-pellucid drops or tears of a pale amber colour. This resin possesses a very agreeable fragrance and a bitterish taste, somewhat like frankincense or turpentine; it is chewed by Indians and traders to cleanse their teeth and mouth and sweeten their breath.” Beware before you try it as Illinois author John Madison wrote, “Pioneers found that compass plant produced a pretty good brand of native chewing gum. It has an odd pine-resin taste that’s pleasant enough, but must be firmed up before its chewed. A couple summers ago I tried some of this sap while it was still liquid. It’s surely the stickiest stuff in all creation and I literally had to clean it from my teeth with lighter fluid.”

Download PDF



Illinois Natural History Survey

1816 South Oak Street, MC 652
Champaign, IL 61820
217-333-6880
cms@inhs.illinois.edu

Terms of use. Email the Web Administrator with questions or comments.

© 2017 University of Illinois Board of Trustees. All rights reserved.
For permissions information, contact the Illinois Natural History Survey.

Staff Intranet
Login