Physocarpus, commonly called ninebark, is a genus of flowering plants in the familyRosaceae, native to North America (most species) and northeastern Asia (one species).
Description
Physocarpus are deciduousshrubs with peeling bark[2] and alternately arranged leaves. The leaves are palmate with 3 to 7 lobes and often toothed edges. The inflorescence is a cluster of bell-shaped flowers with 5 rounded white or pink petals and many stamens. The fruit is a flat or inflated dehiscentfollicle.[3][4]
Physocarpus opulifolius is cultivated as an ornamental plant. Several cultivars have been bred, particularly for foliage of varying colors, including 'Dart's Gold' and 'Luteus', which have yellowish leaves, and 'Monlo' and 'Seward', which have reddish purple foliage.[5]
Taxonomy
Species
There are six[3][6][7] to 20[4] species in the genus. They include:
The genus name Physocarpus comes from the Greek word for "bladder fruit", referring to the inflated fruits of some species.[23] The common name 'ninebark' refers to the peeling bark of mature branches, which comes away in strips.[2]
Cultivation
Propagation is by seeds sown as soon as ripe or they can be stored dry in airtight containers in a cool place for up to a year and then sown. Plants can be divided in the early spring, with a sharp spade or even an axe, chopping right through the middle. Softwood and hardwood cuttings are easy to root.
Garden writers describe few if any problems, but it is not unheard for armies of aphids to attack some varieties. Some seaside specimens exhibit powdery mildew in summer.
References
^Physocarpus Tropicos.org. Missouri Botanical Garden. 22 Jan 2012
^USDA, NRCS (n.d.). "Physocarpus alternans". The PLANTS Database (plants.usda.gov). Greensboro, North Carolina: National Plant Data Team. Retrieved 22 Jan 2012.
^P. amurensis Flora of China, www.eFloras.org 22 Jan 2012
^USDA, NRCS (n.d.). "Physocarpus capitatus". The PLANTS Database (plants.usda.gov). Greensboro, North Carolina: National Plant Data Team. Retrieved 22 Jan 2012.
^P. glabratus Tropicos.org. Missouri Botanical Garden. 22 Jan 2012
^USDA, NRCS (n.d.). "Physocarpus malvaceus". The PLANTS Database (plants.usda.gov). Greensboro, North Carolina: National Plant Data Team. Retrieved 22 Jan 2012.
^USDA, NRCS (n.d.). "Physocarpus monogynus". The PLANTS Database (plants.usda.gov). Greensboro, North Carolina: National Plant Data Team. Retrieved 22 Jan 2012.
^USDA, NRCS (n.d.). "Physocarpus opulifolius". The PLANTS Database (plants.usda.gov). Greensboro, North Carolina: National Plant Data Team. Retrieved 22 Jan 2012.