Above: Compass Plant on the shore of the retaining pond on the corner of Nakoma Road and Manitou Way in Madison, Wisconsin (7/31/20).
Compass Plant - Silphium laciniatum
The common name compass plant was inspired by the "compass orientation" of its leaves. The large leaves are held vertically with the tips pointing north or south (to avoid the full brunt of the sun) and the upper and lower surfaces of the blades facing east or west.
The leaves are deeply divided into linear-oblong lobes.
The Compass Plant is related to Rosinweed (Silphium integrifolium), Basal-leaved Rosinweed (Silphium terebinthinaceum)) and the Cup Plant (Silphium perfoliatum)).
Other Names: prairie compass plant, pilotweed, polarplant, gum weed, cut-leaf silphium, and turpentine plant.
Silphium: old Greek generic name referring to resinous juice.
Above: Compass Plant stem and leaves.
For more information on the Compass Plant, visit Wikipedia.
Or, visit the UW-Madison Wisconsin State Herbarium website page about Compass Plant.
Above: Compass Plant in the UW-Madison Arboretum in Madison, Wisconsin on July 12, 2020.
Above: "Compass Plant along bike path near Glenway intersection in Madison, Wisconsin on August 19, 2020.
Above: Compass Plant in the UW-Madison Arboretum in Madison, Wisconsin on August 20, 2020.
Above: 1913 Compass Plant illustration.