Ninebark, Physocarpus capitatus

In 1806, Meriwether Lewis termed this shrub “Sevenbark” for its stems with seemingly continuous layers of conspicuously peeling bark. However, the name “Ninebark” was the common name that stuck.

A member of the Rose Family, this deciduous shrub superficially resembles a cultivated Snowball Viburnum, for its hemispheric inflorescences composed of numerous white blossoms. Each individual flower has five petals and around 30 stamens - each with colorful pink anthers, prior to their pollen being shed.

Ninebark, which sometimes can grow nearly 12 feet high, has leaves that are 1 to 3 inches across and palmately veined - meaning they resemble small maple leaves with 3 to 5 lobes on each leaf. 

Use a 10X hand lens to see tiny, star-shaped (called stellate) hairs under the leaves. These also occur along the younger stems, and on the slightly reflexed sepals (under the petals of each flower).

The scientific name Physocarpus is Greek for “bladder (or bellows) fruit,” for the plants’ small, but slightly inflated, seed pods. The species epithet capitatus refers to the fact that the flowers are clustered in these showy “capitate” heads.

While Ninebark is found primarily in western Oregon, it also occurs in some scattered locations in the northeastern part of the state. It is most often found just above lakes and streams.  However, these photos of Ninebark were taken by Oregon Wild member Sue Parsons on a June Oregon Wild hike to Angel’s Rest - an otherwise dry, rocky butte in the damp western Columbia River Gorge. Overall, Ninebark ranges from southern Alaska to northern California.

Only one known tribe, the Miwok, reportedly collected the dry seed capsules for food. However, many tribes regarded the plant as an emetic, a poison antidote, with the bark being chewed, and the juice swallowed to induce vomiting.