Pterostyrax hispida: Fragrant Epaulette Tree
Introduction
Fragrant epaulette tree is a deciduous tree which can reach 20 to 30 feet in height with an equal spread but is more often seen smaller. The three- to eight-inch-long by four-inch-wide, light green, oval leaves have a silvery cast on their undersides, and the leaves turn yellow or yellow-green in fall before dropping. Of particular interest are the delicate, creamy white, slightly fragrant blooms which appear in early summer when few other trees are flowering. Hanging in nine-inch-long and four-inch-diameter clusters, these blossoms are quite striking when viewed from below so the tree should be properly situated to take advantage of this display, planting it on a bank along a walkway, in a raised bed, or above a bench. This will also allow the attractive bark to be more easily appreciated, an inner orange/tan color showing through the grey bark at expansion breaks. The seed pods which follow the pendulous blooms are grey, fuzzy, and cling to the branches throughout the winter. They are quite showy and useful in dried flower arrangements.
General Information
Scientific name: Pterostyrax hispida
Pronunciation: teer-oh-STY-racks HISS-pih-duh
Common name(s): Fragrant epaulette tree, wisteria-tree
Family: Styracaceae
USDA hardiness zones: 4B through 8A (Figure 2)
Origin: not native to North America
Invasive potential: not assessed/incomplete assessment
Uses: deck or patio; specimen; shade
Description
Height: 20 to 30 feet
Spread: 20 to 30 feet
Crown uniformity: irregular
Crown shape: vase, spreading
Crown density: dense
Growth rate: moderate
Texture: coarse
Foliage
Leaf arrangement: alternate
Leaf type: simple
Leaf margin: pectinate, serrate
Leaf shape: oblong, ovate
Leaf venation: brachidodrome, pinnate
Leaf type and persistence: deciduous
Leaf blade length: 4 to 8 inches
Leaf color: green
Fall color: yellow
Fall characteristic: not showy
Flower
Flower color: white/cream/gray
Flower characteristics: showy
Fruit
Fruit shape: oval
Fruit length: less than 0.5 inch
Fruit covering: dry or hard
Fruit color: brown
Fruit characteristics: does not attract wildlife; showy; fruit/leaves not a litter problem
Trunk and Branches
Trunk/bark/branches: branches droop; showy; typically multi-trunked; thorns
Pruning requirement: needed for strong structure
Breakage: resistant
Current year twig color: gray
Current year twig thickness: thin, medium
Wood specific gravity: unknown
Culture
Light requirement: full sun
Soil tolerances: clay; sand; loam; slightly alkaline; acidic; well-drained
Drought tolerance: moderate
Aerosol salt tolerance: unknown
Other
Roots: not a problem
Winter interest: yes
Outstanding tree: yes
Ozone sensitivity: unknown
Verticillium wilt susceptibility: unknown
Pest resistance: free of serious pests and diseases
Use and Management
The wide-spreading, upright-spreading branches help to make this a fabulous small shade tree, casting deep shade beneath the tree. Some early pruning may be necessary to remove the lower branches (to allow easier access below the tree) or to control the tree's shape. Seek out this little-known tree for a specimen or group planting which is not likely to be duplicated in the near future due to the rarity of the tree.
Fragrant epaulette tree should be grown in full sun on moist, well-drained soil. It will tolerate both acid and alkaline soils. The trees perform best when they receive no shade, becoming thin and flowering poorly in the shade.
Propagation is by seed.
Pests and Diseases
No pests or diseases are of major concern.