PlantFiles: Hoptree, Stinking Ash, Wafer Ash
Ptelea trifoliata

Hop Tree is a great small understory tree or a shrub that flowers with clusters of small greenish-white slightly fragrant flowers in spring and then makes the wafer-like seeds. It's a host plant for the caterpillars of the Giant Swallowtail and the Two-tailed Tiger Swallowtail, both large, beautiful butterflies. I wish I had lots of these little trees!

I was surprised to see the comments of the scent of this tree. The reason I first noticed it was that in full bloom, the flowers cast their citrusy scent into the air. It drew me all the way across a large garden! It was like being in a orange grove at bloom time.

As for the scent of the foliage, I too find it to be mildly unpleasant, but the scent only manifests itself when a leaf is crushed.

Maybe there are strains of this far flung plant which differ in their scent characteristics?

I have not grown thos plant so I am giving it a neutral rating.

Except in the extreme southern part, wafer ash is found throughout Texas. It can been found natively inhabiting a wide area in the United States including Arkansas, Florida, Louisiana, New York, Oklahoma and through the midwest, Arizona, California, Colorado and Utah. It grows in full sun to heavy shade, is adaptable to various soil types and ranges from dry rocky slopes to valley bottoms.

Classified as a shrub, it sometimes becomes a small tree growing to 18 feet. Its trifoliate leaflets vary in size and shape. The dark green, lustrous leaves may be alternate or opposite and in some varieties pubescent. The dioecious, small, yellowish blooms are somewhat fragrant; although, most of the other parts of the plant have a strong, pungent odor. The blloms appear from March to July. It has whitish to dark gray, bitter tasting bark. The wafer-like, 0.8 to 1 inch samaras (winged, dry, usually one-seeded fruit that does not open on its own to release seeds) ripen in August and September. They remain on the plant on drooping clusters through the winter. Wafer ash can be propagated by seed, grafting or layering. It is seldom used as a landscape plant/

It is a larval food for the swallowtail butterfly. The bark and the root have a number of medicinal uses. The fruit was employed as a substitute for hops in beer production. It has been cultivated since 1784. Now there are many varieties.

Ptelea is hardy enough outdoors in St. Petersburg, Russia (=usda zone 4a). Here it looks like a shrub (2-4m height).

This is a small,deciduous tree or a large shrub depending upon where the plant grows.The bark and leaves are bitter, strongly scented. It has a straight, slender trunk, 6—8 inches in diameter,and seldom reaches a height of more than 20 feet.Has shiny,dark green leaves which turn greenish yellow in fall.The flowers are greenish-white and unpleasantly scented.This tree flowers in June.The fruit matures in September or October.The fruit is small,round, two-seeded,winged and pale green that stay on the tree over the winter.