Scientific: Sapindus saponaria (Synonym: Sapindus thurstonii)
Common: western soapberry, wingleaf soapberry
Family: Sapindaceae
Origin: Distributed across the southern United States from Arizona to South Carolina and Florida. Found in upland slopes and riparian canyons of the Mogollon rim region and into southeast Arizona at elevations between 2,000 and 5,000 feet, and east across the southern United States into Florida. Also, it is native to Hawaii, Mexico south into South America, New Caledonia, and Africa.
Note of origin: Sapindus saponaria is geographically aggregated into two varieties across its native range in the contiguous Unites States; variety drummondii (western soapberry) in the west [named for Thomas Drummond (ca. 1790-1835), a Scottish botanist] and variety saponaria (wingleaf soapberry) in the east.
Local invasive alert: In flood irrigated portions of the Phoenix basin, western soapberry has shown a tendency to 'naturalize' and become an unwanted weed invading large informal hedges.
Pronounciation: Sa-PIN-dus sa-po-NAR-ee-a
Hardiness zones
Sunset 12-17, 19-24
USDA 8 (with cold protection), 9-11 (arid and semi arid region best)
Landscape Use: Small shade tree, floral and foliar accent, background tree
Form & Character: Upright and spreading with age, somtimes rounded, sometimes very assymetrical, lacy and delicate when in fully foliated with a subtle pendulous habit, moist.
Growth Habit: Deciduous, woody, broadleaf perennial tree, rapid grower when young producing succulent green shoots in spring. Eventually reaching heights of 10 to 50 feet (usually only 20-feet tall in Arizona) with lesser to equal spread.
Foliage/Texture: Leaves bright green to 18-inches long, pinnately compound, up to 24 pairs of leaflets, leaflets falcate and lanceolate; fine texture.
Flowers & Fruits: Flowers are terminal, creamy white and small, but are born in uber-copious quantities on elongated branched panicles to 10-inches long. Fruits are a persistent, poisonous yellow drupe that darkens with age.
Seasonal Color: Creamy flowers in May and June, yellow fall color.
Temperature: Tolerant
Light: Full sun
Soil: Prefers moist irrigated soils. In the Phoenix area, grows fastest in former agricultural soils.
Watering: In desert locations, generally irrigate frequently during summer.
Pruning: Typical crown raising as this tree has a somewhat pendulous tendency, especially new branches.
Propagation: Seed, softwood cutting
Disease and Pests: None
Additional comments: This is a seldom-used, colorful tree that is a copious litter producer, especially the senescing flowers and leaves.
Biochemical factoid: The fruit are poisonous containing the alkaloid saponin. This chemical has been used as a soap substitute for washing clothes, but can cause a dermatitis for some people upon skin contact.
