A Prairie Birthday

In one of Aldo Leopold's essays in A Sand County Almanac, he discusses the idea of a Prairie Birthday. He points out that each week during the months of April to September gives way to the blooming of new wildflowers on the prairie and how these "birthdays" should be celebrated. There is one particular flower he discusses the most; and while we may have missed the celebration of its first bloom in July, the Compass Plant is still in full bloom.

Silphium Laciniatum

The official name of the compass plant is Silphium laciniatum, but is sometimes referred to as the compass flower or rosinweed. Even though these plants might be related to the sunflower, don't get them mixed up! One major difference between the two plants is the sticky sap, or rosin, you can find in in the compass plant's stem - hence the nickname rosinweed. This rosin was once used by Native American children as chewing gum to clean their teeth and freshen their breath. Compass plants can grow to be around 10 feet tall with leaves that are 15 - 24 inches in length! And for every inch above ground, imagine that their roots are extending about the same distance below! The bright yellow flowers at the top of the stem are more modestly-sized, ranging from 2 to 4 inches across. You can find these lovely plants anywhere in the East-Central region of North America, mostly in tall grass prairies.

Sense of Direction

While the nickname "rosinweed" has an obvious origin, the name "compass plant" might not seem to make much sense with this flower at first. This name derives from the discovery that the leaves on the plant almost always point in the North-South direction (the key words are "almost always" - so don't get rid of your orienteering tools just yet). Once early settlers on the central plains realized this, they were able to use the plants as a guide to help them know where they were going - just like a compass!

Compass Plant at the
Aldo Leopold Nature Center

These plants have a long history in North America, being used as herbal medicines and teas by the Native Americans, and then as compasses by American settlers. No wonder Aldo Leopold was so amazed by these resilient plants! He appreciated these plants as a symbol of Wisconsin's native prairie, and you can enjoy these beauties too. Go exploring in a nearby grassland, prairie, or park. See if their leaves really can point you in the right direction. The Aldo Leopold Nature Center is a great place to begin your quest - their prairie is blooming full of compass plants these days - or take a walk through the UW Arboretum or Olbrich Botanical Gardens for a more extensive feel of the native prairie plants we have here in Wisconsin.