Atlantic Ninebark (Intermedius)

The Atlantic Ninebark (Intermedius) is generally described as a perennial shrub. This is native to the U.S. (United States) .

Uses of : Landscaping, Medicinal, Culinary, etc.

Atlantic ninebark is cultivated in the US and in Europe for its foliage, clusters of white flowers in the spring, and red fruits in the autumn. Various cultivars have been selected for compactness of growth, yellow or golden leaf color, and greater size and showiness of flower clusters.

Flowers of Atlantic ninebark are an excellent nectar source, and the fruits are eaten by many species of birds. Physocarpus monogynus of the southwestern US, was used by Indians to relieve pain – the roots were boiled to softness and placed on sores and lesions as a poultice.

General Characteristics

General: Rose Family (Rosaceae). Native shrubs growing 1-3 meters tall, sometimes tree-like, with wide-spreading, recurved branches, the twigs brown to yellowish, glabrous; bark brown to orangish, peeling into thin strips or broader sheets on larger trunks. Leaves are deciduous, alternate, simple, ovate to obovate or nearly round, 3-12 cm long, with 3(-5) shallow, palmate-veined lobes, basally truncate or cuneate, on petioles 1-3 cm long, glabrous above and mostly so beneath but sometimes with a sparse covering of stellate hairs beneath, with crenate or dentate margins. Inflorescence of numerous flowers found in rounded clusters 2.5-5 cm wide; flowers 7-10 mm wide, calyx cup-shaped, glabrous or with stellate hairs, 5-lobed; petals 5, white or pinkish; styles 5; stamens 30-40. Fruit is compressed but inflated, ovoid, 8-12 mm long, shiny, red at maturity, glabrous or hairy, with papery but firm walls, splitting along two sides, in clusters of (2-)3-5 per flower; seeds 2-4. The common name comes from the bark, which continually molts in thin strips, each time exposing a new layer of bark, as if it had “nine lives.” This species flowers in May-July and fruits in May-July.

Variation within the species: two varieties are sometimes recognized within the species. Var. intermedius (Rydb.) B.L. Robins. has fruits that are persistently covered with stellate hairs, while var. opulifolius has glabrous fruits. Var. intermedius is the more western form, occurring from New York, Ontario, Ohio, Indiana, Illinois, Missouri, and Arkansas to the westernmost localities for the species. Var. opulifolius is broadly distributed in the east, to Minnesota and Iowa, and in Canada from New Brunswick and Nova Scotia to Manitoba. Intergradation in the fruit character makes it difficult to discern clear

Required Growing Conditions

Atlantic ninebark occurs widely in eastern North America, in Canada from Manitoba to the easternmost provinces, and in the US from Minnesota to Arkansas (with outlying occurrences in Colorado, North Dakota and South Dakota to Oklahoma) and eastward to the Atlantic states. It has not been recorded from Texas, Louisiana, or Mississippi. For current distribution, please consult the Plant Profile page for this species on the PLANTS Web site.

Adaptation The plants are found on moist soils in thickets, along streams in sand or gravel bars, and on rocky slopes and bluffs. Dirr (1997) observes that “the species is adaptable to all conditions, probably even nuclear attacks, and once established, requires a bulldozer for removal.”

Cultivation and Care

Atlantic ninebark can be propagated from cuttings or seeds, which germinate without pre-treatment. It transplants readily and apparently grows easily over a range of light, moisture, and acidity.

General Upkeep and Control

Information on fire response is not available for Atlantic ninebark but shrubs of the western US species Physocarpus malvaceus (Greene) Kuntze readily re-sprout after intense surface burns (Lea & Morgan 1993).

Plant Basics
General Type Shrub
Growth Duration Perennial
Plant Nativity Native to U.S.

Source: USDA, NRCS, PLANTS Database,
National Plant Data Center, Baton Rouge, LA 70874-4490 USA