Eastern leatherwood (Dirca palustris) is a shrub with many interesting features, including twigs so flexible they can be tied into knots. Both the twigs and strips of its very tough, flexible bark were used as twine-like materials by some indigenous peoples.
Dirca palustris [pdf] is a member of the daphne family (Thymelaeaceae), which includes the many ornamental shrubs in the genus Daphne. The Flora of North America notes that one trait of daphne family members is that the wood is poorly lignified, that is, the lignin that normally stiffens cell walls in woody tissue don’t develop well, hence the extreme stem flexibility. (A nomenclatural note: The family name comes from another of its genera, Thymelaea, and is unrelated to the herb thyme [Thymus vulgaris], which is a member of the mint family [Lamiaceae].)
Eastern leatherwood has a large native range covering much of the eastern United States and part of southeastern Canada, though it is not especially common anywhere in its range. It grows in forest understories and prefers moist sites. Leatherwood starts blooming early in the spring, producing many small, dangling, light yellow flowers. This early flowering and subsequent early leaf-out give it a jump start before overstory trees start casting shade. Leatherwood grows about 3 to 6 feet (0.9 to 1.8 meters) tall and typically has one or just a few main stems, often giving it a charming “mini-tree” appearance (see accession 487-2002*A in the Leventritt Shrub and Vine Garden). Its rounded leaves are bright green in summer and turn yellow in the fall. Though slow growing, eastern leatherwood makes a fine addition to woodland or shade gardens where it can be appreciated year ’round.