Ptelea trifoliata

Ptelea trifoliata, the hop tree or wafer ash, is a unique and underappreciated native, a small, bushy deciduous tree of eastern and central North America. Highly adaptable, the plant takes dry, rocky ground as readily as moist, well-drained sites, which makes the hop tree a fine choice for naturalized landscapes, pollinator gardens, and woodland edges.

The distinctive trifoliate leaves, each of three leaflets on a single stalk, mark the hop tree as a member of the citrus family, Rutaceae, and release a pleasant citrusy scent when crushed. That aromatic oil helps deter deer, and the same family lineage makes the plant a larval host for the giant swallowtail (Papilio cresphontes) and other swallowtail butterflies, a real prize for a butterfly garden.

In late spring the branches carry loose clusters of small, pale yellow-green flowers, modest to look at but intensely and sweetly fragrant, drawing bees, butterflies, and other pollinators. The flowers give way to flat, papery, wafer-like winged seeds, three-quarters to an inch across, that turn from green to golden-tan and hang on the tree well into winter, drifting on the wind to sow. The seeds were historically used as a substitute for hops in brewing, the source of the common name.

The root bark carries a quieter history. Nineteenth-century Eclectic physicians and earlier Native healers valued it as a bitter tonic, praised by some as comparable to quinine, and as a soothing remedy for a delicate stomach.

Tough, drought tolerant, and easy to grow, the hop tree suits a native or butterfly garden, a woodland edge, a xeriscape, or a restoration planting, in full sun to part shade and well-drained soil. Give room for the rounded, shrubby frame, remove suckers if a single trunk is wanted, and enjoy a hardy, wildlife-rich native with fragrance in spring and persistent wafers into winter.