Sep. 13, 2019

compass plant, Silphium laciniatum

Compass plant is a tall herb, around head high. Variation among members of the genus is fascinating. They may have leaves on the stem or not. The leaf shape can be an ordinary lance shape, or narrower, or lobed, or deeply lobed like this, or united around the stem. Beyond that, compass plant leaves point north and south. Within a couple of weeks after they sprout , they react to the morning sun by orienting themselves. Then they stay that way. This apparently makes them more efficient in retaining moisture. Compass plant grows in open areas, particularly prairies, in AL, AR, CO, IA, IL, IN, KS, KY, LA, MI(T), MN, MO, MS, NC, NE, NM, NY, OH(E), OK, PA, SD, TN(T), TX, VA, WI, and ON. Often planted in prairie restorations, as this one was in Lenawee Co MI, 7/30/10.