''Rosa pisocarpa'' is a species of

rose A rose is either a woody perennial flowering plant of the genus ''Rosa'' (), in the family Rosaceae (), or the flower it bears. There are over three hundred species and tens of thousands of cultivars. They form a group of plants that can be ...

known by the common name cluster rose or swamp rose. It is native to western North America 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, ...

to northern

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

, where it generally grows in moist habitats. It is a

shrub A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...

sometimes forming a thicket, and growing up to 2.5 meters tall. The stems can be dark red or blackish and are often studded with straight, paired prickles at nodes. The leaves are each made up of several toothed oval leaflets, the terminal leaflet up to 4 centimeters long. The

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

is a cyme of up to 10 flowers with pink petals each up to 2 centimeters in length. The fruit is a

rose hip The rose hip or rosehip, also called rose haw and rose hep, is the accessory fruit of the various species of rose plant. It is typically red to orange, but ranges from dark purple to black in some species. Rose hips begin to form after pollinat ...

about a centimeter wide. The hips are pear- or egg-shaped and borne in clusters, and are decorative in fall and early winter, when they are red or reddish-purple and contrast with yellow foliage. Fall foliage can be yellow or dark red. Rosa pisocarpa fall color

Ecology

''Rosa pisocarpa'' has a wetland indicator status of FAC for the Pacific Northwest (region 9) and FACU for California (region 0). It grows in full sun in the northern and wetter portions of its range, but also tolerates partial shade, and can grow in dry or lean soils. ''Rosa pisocarpa'' grows in riparian areas, along roadside ditches, in powerline right-of-ways, along

fencerow In agriculture, fences are used to keep animals in or out of an area. They can be made from a wide variety of materials, depending on terrain, location and animals to be confined. Most agricultural fencing averages about high, and in some places ...

s and

hedgerow A hedge or hedgerow is a line of closely spaced shrubs and sometimes trees, planted and trained to form a barrier or to mark the boundary of an area, such as between neighbouring properties. Hedges that are used to separate a road from adjoini ...

s, in wetland buffers and woodlands. ''Rosa pisocarpa'' is used in wetland restorations and in native plant landscaping. Its thorny thickets and numerous, persistent hips provide shelter and food for birds and other small wildlife. Deer browse new stems and foliage. ''Rosa pisocarpa'' hosts gall-making wasps of the family Cynipidae, genus ''Diplolepis'', in the insect class

Hymenoptera Hymenoptera is a large order (biology), order of insects, comprising the sawfly, sawflies, wasps, bees, and ants. Over 150,000 living species of Hymenoptera have been described, in addition to over 2,000 extinct ones. Many of the species are Par ...

. Two species are ''D. polita'', which makes bristly round red or green

galls Galls (from the Latin , 'oak-apple') or ''cecidia'' (from the Greek , anything gushing out) are a kind of swelling growth on the external tissues of plants, fungi, or animals. Plant galls are abnormal outgrowths of plant tissues, similar to be ...

on leaves, and ''D. rosae'', the mossy rose gall, which makes large, mossy, feathery, greenish or yellowish growths on stems. Diplolepis-rosae

References

External links

Jepson Manual TreatmentUSDA Plants ProfilePhoto galleryUW Burke HerbariumHelpMeFind Roses
{{Taxonbar, from=Q3017700 pisocarpa Flora of North America