''Physocarpus malvaceus'' is a species of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

in the

rose family Rosaceae (), the rose family, is a medium-sized family of flowering plants that includes 4,828 known species in 91 genera. The name is derived from the type genus ''Rosa''. Among the most species-rich genera are '' Alchemilla'' (270), ''Sorbus ...

known by the common name mallow ninebark. It is native to western North America, where its distribution extends from

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

Nevada Nevada ( ; ) is a state in the Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the 7th-most extensive, ...

Wyoming Wyoming () is a state in the Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to the s ...

.Habeck, R. J. 1992
''Physocarpus malvaceus''.
In: Fire Effects Information System, nline U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory. This plant is a deciduous shrub usually growing up to 2.1 meters tall, sometimes reaching 3 meters.''Physocarpus malvaceus''.
International Institute of Tropical Forestry. It can form dense

thicket A thicket is a very dense stand of trees or tall shrubs, often dominated by only one or a few species, to the exclusion of all others. They may be formed by species that shed large numbers of highly viable seeds that are able to germinate in t ...

s. The branches are hairless, and older ones have shreddy bark. The leaves have three to five lobes and serrated edges. Dark green when mature, they turn brownish red by early fall. The

inflorescence An inflorescence is a group or cluster of flowers arranged on a Plant stem, stem that is composed of a main branch or a complicated arrangement of branches. Morphology (biology), Morphologically, it is the modified part of the shoot of sperma ...

is a

corymb Corymb is a botanical term for an inflorescence with the flowers growing in such a fashion that the outermost are borne on longer pedicels than the inner, bringing all flowers up to a common level. A corymb has a flattish top with a superficial ...

of flowers that have white petals measuring about 4 millimeters in length. The fruit is a follicle roughly one centimeter long.''Physocarpus malvaceus''.
Washington Burke Museum. This shrub grows in forests, woodlands, and oak scrub. The forests are dominated by

subalpine fir ''Abies lasiocarpa'', the subalpine fir or Rocky Mountain fir, is a western North American fir tree. Description ''Abies lasiocarpa'' is a medium-sized evergreen conifer with a very narrow conic crown, growing to tall, exceptionally , with a t ...

(''Abies lasiocarpa''),

grand fir ''Abies grandis'' (grand fir, giant fir, lowland white fir, great silver fir, western white fir, Vancouver fir, or Oregon fir) is a fir native to the Pacific Northwest and Northern California of North America, occurring at altitudes of sea leve ...

(''A. grandis''),

Engelmann spruce ''Picea engelmannii'', with the common names Engelmann spruce, white spruce, mountain spruce, and silver spruce, is a species of spruce native to western North America. It is mostly a high-altitude mountain tree but also appears in watered canyon ...

(''Picea engelmannii''),

Douglas-fir The Douglas fir (''Pseudotsuga menziesii'') is an evergreen conifer species in the pine family, Pinaceae. It is native to western North America and is also known as Douglas-fir, Douglas spruce, Oregon pine, and Columbian pine. There are three va ...

(''Pseudotsuga menziesii'') and

ponderosa pine ''Pinus ponderosa'', commonly known as the ponderosa pine, bull pine, blackjack pine, western yellow-pine, or filipinus pine is a very large pine tree species of variable habitat native to mountainous regions of western North America. It is the ...

(''Pinus ponderosa''). It is associated with plant species such as oceanspray (''Holodiscus discolor''), common snowberry (''Symphoricarpos albus''), mountain snowberry (''S. oreophilus''), white spirea (''Spiraea betulifolia''), serviceberry (''Amelanchier alnifolia''), Oregon-grape (''Mahonia repens''), and

pinegrass ''Calamagrostis rubescens'' is a species of grass known by the common name pinegrass. Distribution It is native to western North America, including Canada from British Columbia to Manitoba and the United States from California to Colorado. It ca ...

(''Calamagrostis rubescens''). This shrub is codominant with Douglas-fir in a common

plant community A plant community is a collection or association of plant species within a designated geographical unit, which forms a relatively uniform patch, distinguishable from neighboring patches of different vegetation types. The components of each plant ...

. This shrub is a

pioneer species Pioneer species are hardy species that are the first to colonize barren environments or previously biodiverse steady-state ecosystems that have been disrupted, such as by wildfire. Pioneer flora Some lichens grow on rocks without soil, so ...

that increases after disturbance and decreases as the overstory grows back and shades it out. It grows rapidly after events such as

wildfire A wildfire, forest fire, bushfire, wildland fire or rural fire is an unplanned, uncontrolled and unpredictable fire in an area of combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identi ...

, sprouting up from its rhizomes. It is considered a "fire-resistant" plant. It survives fire and resprouts, becoming more common on burned sites than unburned. This is not a favored food plant among wild and domesticated herbivores. It does provide good cover for small animals. The Dusky Flycatcher (''Empidonax oberholseri'') nests in it. This plant is known to hamper regeneration of forest habitat after disturbance such as fire or logging. It outcompetes new conifer seedlings. It is controlled with herbicide spray in some regions.

References

External links

USDA Plants Profile for ''Physocarpus malvaceus'' (mallow ninebark)
{{Taxonbar, from=Q7189745 malvaceus Flora of the Northwestern United States Flora of Western Canada Flora of Nevada Flora of Utah Flora of the Rocky Mountains Taxa named by Edward Lee Greene