Poncirus trifoliate (Trifoliate orange)
A close relative of a commercially used species of citrus, Trifoliate orange is often used as the rootstock for commercial oranges, as it imparts some cold hardiness. Trifoliate orange reveals great fall color and winter interest. Note its contorted spiny branches and its fruit, which hold into winter. Also check out the cultivar ‘Flying Dragon,’ a dwarf variety with even more branch contortion. Find it at the Visitors Center to the right of the stairs up to the parking lot.
Oxydendrum arboreum (Sourwood)
With shades of scarlet, maroon, and plum persisting through late autumn, Oxydendrum arboreum is a must-see for a fall-color tour of the arboretum! Find it on the Wildwood Trail heading west after the trail crosses Knights Blvd.
Franklinia altamaha (Franklin Tree)
This small tree, named after Benjamin Franklin and the Altamaha River in southeastern Georgia, where it was found in 1765, has long, dark-green leaves that turn red, orange, or pink in fall. Its most striking feature? Its five-petal fragrant white flowers, containing showy clusters of yellow stamens. The tree flowers from late summer until frost. Find it on the Wildwood Trail near the Vietnam Veterans Memorial.
Cotinus obovatus (American Smoke Tree)
This native of the Appalachians is also well-suited to the Pacific Northwest. The drought-tolerant shrub can grow to 20 feet. Its range of color includes red, pink, orange, and yellow. Look nearby for the interesting hybrid cultivars 'Grace' and 'Golden Spirit." Find it on the Hawthorn Trail near the intersection with the Walnut Trail.