Loosely branching deciduous shrubs with quickly shredding brown bark. Twigs terete, 5-lined at the nodes, slender; pith large, brownish, round, continuous. Buds small, solitary, sessile, conical-oblong or ovoid, with about 5 loose scales. Leaf-scars alternate, elliptical or 3-lobed; bundle-traces 3, unequal, the lower one larger than the others; stipule-scars small.
Fig. 124. Physocarpus opulifolius.
1. P. opulifolius (L.) Maxim. Ninebark. A shrub 1-3 m.high, with long branches, the old bark loose and separating in numerous thin layers (whence the common name); buds pointed, appressed; twigs glabrous; fruit, as clustered small dry follicles, present in winter. Shores and rocky banks, Quebec to Ontario, Minnesota and Colorado, south to South Carolina and Arkansas (Fig. 124).