Page authors: Don Knoke, David Giblin
Physocarpus malvaceus
mallow ninebark, mallow-leaf ninebark

Distribution: Occurring east of the Cascades crest in eastern Washington; British Columbia to Oregon and Nevada, east to Alberta, Montana, Wyoming, and Colorado.

Habitat: Canyons and hillsides, grasslands, ponderosa pine and Douglas-fir forest openings and edge.

Flowers: May-July

Origin: Native

Growth Duration: Perennial

Conservation Status: Not of concern


Spreading to erect shrub 0.5-2 m. tall, the branches angled, usually glabrous.


Leaves alternate, petiolate, the blades ovate to cordate, 3-5 lobed, the lobes bi-serrate, 4-7 cm. long and broad, dark green and glabrous above and paler below, with stellate hairs.


Flowers rather numerous in terminal clusters; calyx hemispheric, with stellate hairs, the 5 lobes ovate-lanceolate, 3 mm. long, somewhat reflexed; petals 5, white, sub-orbicular, 4 mm. long, spreading; stamens about 30, equaling the petals; pistils 2, attached to each other at least half way, strongly stellate-haired.


Fruit a glabrous follicle, 7-11 mm. long, swollen.

Accepted Name:
Physocarpus malvaceus (Greene) Kuntze
Publication: Revisio Generum Plantarum 1: 219. 1891.

Synonyms & Misapplications:
Neillia malvacea Greene
Neillia monogyna var. malvacea M.E. Jones
Neillia torreyi Hook. f.
Opulaster cordatus Rydb.
Opulaster pauciflorus (Torr. & A. Gray) A. Heller
Opulaster pubescens Rydb.
Physocarpus pauciflorus (Torr. & A. Gray) Piper
Spiraea opulifolia var. pauciflora T. & G.
Spiraea pauciflora Nutt.
Additional Resources:

PNW Herbaria: Specimen records of Physocarpus malvaceus in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Physocarpus malvaceus checklist entry.

E-Flora BC: Physocarpus malvaceus atlas page.

CalPhotos: Physocarpus malvaceus photos.

USDA Plants: Physocarpus malvaceus information.

35 photographs:
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