''Spiraea douglasii'' is a species of flowering plant 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 ...

native to western North America. Common names include hardhack, hardhack steeplebush, Douglas' spirea, douglasspirea, steeplebush, and rose spirea.

Description

''Spiraea douglasii'' is a woolly shrub growing tall from rhizomes, forming dense riverside thickets. The leaves are long and toothed toward the tips. They are alternately arranged, and the undersides are whitish with prominent veins. Large clusters of small, deep pink flowers form spires in early summer, later turning dark and persisting. The seeds are long and are dispersed by animals and strong winds.

Distribution and habitat

The plant is native to western North America from

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S. ...

across southwestern Canada and the

Pacific Northwest The Pacific Northwest (sometimes Cascadia, or simply abbreviated as PNW) is a geographic region in western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Tho ...

. It has spread to many other places as an invasive species. It was introduced to Europe as early as 1803, and is considered to be especially invasive in Denmark and Latvia. It is also found in France, Ireland, Slovenia, Sweden, the United Kingdom, Belgium, Germany and Poland. It occurs most often in

riparian A riparian zone or riparian area is the interface between land and a river or stream. Riparian is also the proper nomenclature for one of the terrestrial biomes of the Earth. Plant habitats and communities along the river margins and banks a ...

habitat types, such as swamps, streambanks, bogs and mudflats.US Forest Service Fire Ecology
/ref> It grows best on moist or semiwet soils with good drainage. It tolerates a variety of soil types as well as gravelly substrates. Spirea is shade-intolerant, and therefore grows primarily in open

marsh A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found a ...

es among

sedges The Cyperaceae are a family of graminoid (grass-like), monocotyledonous flowering plants known as sedges. The family is large, with some 5,500 known species described in about 90 genera, the largest being the "true sedges" genus ''Carex'' wit ...

horsetails ''Equisetum'' (; horsetail, snake grass, puzzlegrass) is the only living genus in Equisetaceae, a family of ferns, which reproduce by spores rather than seeds. ''Equisetum'' is a " living fossil", the only living genus of the entire subclass ...

, wild blueberries, and other swamp flora, as well as in seral communities.

Ecology

Spirea foliage is browsed by

black-tailed deer Two forms of black-tailed deer or blacktail deer that occupy coastal woodlands in the Pacific Northwest of North America are subspecies of the mule deer (''Odocoileus hemionus''). They have sometimes been treated as a species, but virtually all r ...

, but is not very palatable to livestock and only eaten by them occasionally. The flowers provide nectar for hummingbirds, and small birds eat the seeds which persist into the winter when food is less plentiful. Spirea provides nesting habitat for birds such as

marsh wren The marsh wren (''Cistothorus palustris'') is a small North American songbird of the wren family. It is sometimes called the long-billed marsh wren to distinguish it from the sedge wren, also known as the short-billed marsh wren. Taxonomy The ma ...

s, and is a component of grizzly bear habitat. It is moderately fire-resistant, as many of the marshes across its native range would historically dry up by midsummer and be susceptible to fire. If the above-ground portion of the plant is killed, it can sprout from the stem base or rhizomes after a wildfire. It may hybridize with white spirea (''S. betulifolia'') to form pyramid spirea (''S. x pyramidata'' Greene). As an invasive species, the species decreases biodiversity, colonizing wetlands with dense monocultural thickets to the detriment of other plants.

Uses

Native Americans found used the plant for making

broom A broom (also known in some forms as a broomstick) is a cleaning tool consisting of usually stiff fibers (often made of materials such as plastic, hair, or corn husks) attached to, and roughly parallel to, a cylindrical handle, the broomstick. I ...

s and hanging seafood to cook.''Spiraea douglasii''.
Native American Ethnobotany. University of Michigan, Dearborn. The plant is used as an ornamental in

landscaping Landscaping refers to any activity that modifies the visible features of an area of land, including the following: # Living elements, such as flora or fauna; or what is commonly called gardening, the art and craft of growing plants with a goal ...

, where it grows best in sunny, moist places. Spirea is recommended for riparian revegetation projects in the Pacific Northwest, as it is hardy and grows quickly.

References

External links

Jepson Manual TreatmentWashington Burke MuseumPhoto gallery
{{Taxonbar, from=Q159902 douglasii Flora of the Northwestern United States