Above: Field Pennycress near retaining pond on corner of Manitou Way and Nakoma Road in Madison, Wisconsin (5/5/21).
Field Pennycress - Thlaspi arvense
Field Pennycress is a common weed that is part of the mustard family. It is an introduced/naturalized plant in Wisconsin that grows in disturbed sites. It rarely invades undisturbed natural habitats.
Whereas, the flower is not all that interesting, the penny-shaped seed pods are distinctive and are often used in flower arrangements.
Field Pennycress grows 4"-20" tall. The white flowers heads create a dense raceme with numerous small flowers in each head. Each small flower is about 1/8" side and has four petals.
Blooms April-June.
Above: Field Pennycress with distictive seed pods in Wingra Park on shore of Lake Wingra (6/20/20).
For more information on the Field Pennycress, visit Wikipedia.
Or, visit the UW-Madison Wisconsin Herbarium online virtual flora website page on Field Pennycress.
Or, visit the UW-Madison Wisconsin Horticulture Division of Extension website page about Field Pennycress.
Field Pennycress
Thlaspi arvense
Above: Field Pennycress next to Oak Savanna parking lot in Madison, Wisconsin (5/07/21).
Above: Field Pennycress near retaining pond on corner of Manitou Way and Nakoma Road in Madison, Wisconsin (5/05/21)
Above: Field Pennycress next to playground in Wingra Park in Madison, Wisconsin (5/5/21).
Above: Field Pennycress near retaining pond on corner of Manitou Way and Nakoma Road in Madison, Wisconsin (5/4/21).
Above: Field Pennycress near retaining pond on corner of Manitou Way and Nakoma Road in Madison, Wisconsin (5/20/21).
Above: Field Pennycress near retaining pond on corner of Manitou Way and Nakoma Road in Madison, Wisconsin (5/17/22).
Above: Field Pennycress near retaining pond on corner of Manitou Way and Nakoma Road in Madison, Wisconsin (6/12/22).
Above: 1906 Field Pennycress botanical illustration
Above: 1917 Field Pennycress botanical illustration
Above: 1796 Field Pennycress botanical illustration
Above: Field Pennycress specimen collected on October 1958 near Potosi, Wisconsin.