Mexican Buckeye, Ungnadia speciosa: Large multi-trunk shrub or small-medium tree with year-round interest
Description: Mexican Buckeye, Ungnadia speciosa, is native to Central, South and West Texas where it is found in limestone outcrops. It ranges into New Mexico and is found as far east as Dallas. It is usually 8-15 ft tall and multi-trunked with gray to brown bark that may become textured with age. Mexican Buckeye has pinnate leaves, with an individual leaf having 2-6 paired leaflets and a single terminal one. The leaflets are narrow to ovate with serrated margins and are up to 5 inches long, making the overall leaf up to 12 inches long. The foliage is light bronze when Mexican Buckeye first leafs out in the spring, becomes green during the growing season and turns golden yellow in the fall.
Flowers and Seeds: Mexican Buckeye blooms in late winter/early spring. The pink to rose to mauve flowers emerge at the same time as the light bronze leaves. From a distance, Mexican Buckeye may resemble Redbud when it is in flower. In the fall, Mexican Buckeye produces attractive 3-lobed reddish-brown capsules containing 1-3 brown or black shiny seeds that are 1/2 inch in diameter. These may persist throughout the winter, adding interest. The capsule and seeds are reminiscent of true buckeye trees, although Mexican Buckeye is an unrelated species in the Soapberry family.
Planting sites: Mexican Buckeye thrives in full to partial sun. It requires neutral to alkaline soil pH.
Watering Instructions: Mexican Buckeye should be given supplemental water at the time that it is first planted. After it is established, it is drought tolerant and suitable for xeriscaping. It should have adequate drainage; it will not tolerate “wet feet.”
Comments: Mexican Buckeye’s foliage and fruit are toxic to people and livestock and will not be browsed by deer. Its nectar is used by bees to produce a fragrant edible honey. It is a host for the Henry’s Elfin butterfly and is attractive to other butterflies. Mexican Buckeye can be maintained as a small tree if the additional basal trunks are pruned each spring. If not pruned, it will become an attractive tall spreading shrub, suitable for the back of the garden or as a deciduous screen. Mexican Buckeye can be propagated by seed; it is slow-growing and new plants grown from seed may not flower for 4-5 years. Consider planting Mexican Buckeye instead of exotic, over-used Crapemyrtle and Red tip Photinia.
Written by Dr. Becca Dickstein