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Leaves and seeds of wafer ash.

Wafer-ash is a small, native tree or large shrub that produces small fragrant flowers and wafer-like winged seeds, similar to elms. It is a good plant for naturalizing or woodland landscapes. Despite the name, this tree is not a true ash tree and is unaffected by the emerald ash borer.

This species is native to the Chicago region according to Swink and Wilhelm's Plants of the Chicago Region, with updates made according to current research.  

Botanical name:

Ptelea trifoliata

All common names:

Wafer-Ash, Hop tree, Common Hoptree, Stinking Ash, Water-Ash

Family (English):

Citrus, Rue

Family (Botanic):


Tree or Plant Type:

  • Shrub,
  • Tree


  • Deciduous (seasonally loses leaves)

Native Locale:

  • Chicago area,
  • Illinois,
  • North America

Landscape Uses:

  • Massing,
  • Mixed border,
  • Specimen

Size Range:

  • Small tree (15-25 feet),
  • Compact tree (10-15 feet),
  • Large shrub (more than 8 feet)

Light Exposure:

  • Full sun (6 hrs direct light daily),
  • Partial sun/shade (4-6 hrs light daily),
  • Full shade (4 hrs or less of light daily)

Hardiness Zones:

  • Zone 4,
  • Zone 5 (Chicago),
  • Zone 6,
  • Zone 7,
  • Zone 8,
  • Zone 9

Soil Preference:

  • Moist, well-drained soil


  • Occasional drought,
  • Alkaline soil,
  • Clay soil,
  • Road salt

Seasons of Interest:

  • mid spring,
  • late spring,
  • early summer,
  • midsummer

Flower Color & Fragrance:

  • White

Shape or Form:

  • Irregular,
  • Multi-stemmed,
  • Round

Growth Rate:

  • Moderate

More Information:

Size & Form

A small, native rounded tree or large shrub growing 15 to 20  feet high and wide.
Despite the name, this tree is not an ash tree and is unaffected by the emerald ash borer.

Tree & Plant Care

Adaptable to sun or shade and moist soil types, but prefers moist, well-drained soil
Plants have a tendency to sucker.

Disease, pests, and problems

Leaf spots and rust; nothing serious.

Native geographic location and habitat

C-Value: 8
Grows in rich woodlands, forest edges,  and thickets in moist to gravelly places.
Native  to Ontario, New York to Florida west into Minnesota.

Bark color and texture 

Mature bark is dark brown with raised lenticels. Young plants have a smooth, reddish-brown bark.

Leaf or needle arrangement, size, shape, and texture

Alternate, compound, trifoliate three leaflets) , 2 to 6 inches long, lustrous dark green leaves changing to yellow fall color.
Petioles are as long as the leaflets.
Crushed leaves have a pleasant aromatic scent.

Flower arrangement, shape, and size

Small, 2 to 3 inches clusters (corymbs) yellow-green fragrant flowers.
May into June. Not particularly showy.

Fruit, cone, nut, and seed descriptions

Light brown circular samaras (winged papery seeds) at the tips of branches in late summer, persisting into winter.

Location of Ptelea trifoliata (Wafer-ash) at the Arboretum