Physocarpus malvaceus
(Mallow Ninebark)
[Kuntze (Greene)]

Subclass: Rosidae
Order: Rosales
Family: Rosaceae
Family Description: Rose

Key Characteristics:
The bark peels or shreds, thus the name, Ninebark.
  • The 3-5 lobed leaves are sharply toothed, ovate, slightly cordate, dark green adaxially, but paler and stellate pubescent abaxially.
  • The leaves are approximately 2-8 cm long and 2-8 cm wide and doubly crenate.
  • The 5-30 flowers are arranged in terminal corymbs each on a pedicel up to 2.3 cm long.
  • The hypanthium, and pistil are densely stellate pubescent.
  • The sepals vary from 2.2 to 4.6 mm long and the white petals are 3.3-6.7 mm long and 1.5-4.8 mm wide.
  • The two follicles are fused up to about ½ of their 4.9-6 mm length.

General Description:
A small shrub 0.5-2 M tall with glabrous to stellate hairy twigs of drier woodlands east of the Cascade range. The bark peels or shreds, thus the name, Ninebark.

South central British Columbia east through southwest Alberta southward through central Washington, eastern Oregon east of the Cascade Mountains, Montana, Wyoming, Idaho and Utah.

Moist slopes, along streams, and moist woods, Ponderosa Pine and Douglas Fir woodlands and canyon bottoms; associates are aspen, and mixed conifer stands in elevations from 1600 to 3300 meters.

This plant is sometimes cultivated where water is a limiting factor. Other than incidental browsing by big game, no uses are reported.
Photos and Information written by Dr. Karl E. Holte,© 2002