noun
also compass flower
: any of several plants whose leaves or branches are arranged on the axis so as to indicate the cardinal points of the compass: as
a. : a rosinweed ( Silphium laciniatum )
b. : a prickly lettuce ( Lactuca scariola )
c. : prairie bird's-foot trefoil
d. : a low tufted white-woolly yellow-flowered composite herb ( Wyethia ovata ) of California