Gerald L. Klingaman
Family
Annonaceae
Botanical Name
Asimina triloba
Plant Common Name
Pawpaw
General Description
The northernmost representative of the otherwise tropical fruit family, Annonaceae, pawpaw is beloved for its interesting foliage and odd-tasting, edible fruit. The native distribution of this small tree is from the very southernmost reaches of Ontario, Canada, south to Florida, and westward to Texas. Natural populations inhabit bottomlands, floodplains and ravines. This species is quite common in many areas of the country but is listed as a species of concern in others.
Large, oval leaves with pointed tips alternate each other on slender branches of pawpaw. The leaves are medium to deep green and turn yellow to orangish red in fall. New twig growth is covered with coppery hairs. Pawpaw bears flowers on the previous year’s wood. These emerge in spring before (or just as) the new leaves emerge. The blooms are sometimes borne in groups. Each is nodding, cup-shaped, maroon or purple-brown and has a foul smell. This fetid odor attracts flies and beetles, which pollinate the self-infertile flowers.
Pawpaw bears some of the largest edible fruit of any other native North American tree. The large, oblong fruits are almost mango-shaped and technically "true berries." They have a thick, greenish skin than gives on the surface when they are ripe. The yellow, custard-like flesh inside is soft and has many large, dark brown seeds embedding within. Some say it tastes like banana crossed with a pineapple, while others say it tastes like old, somewhat fetid bananas. The fruits may cause stomach problems in some people.
Pawpaw saplings grow best when planted in filtered sun, while older trees grow and produce best in sunny or partially sunny sites. They grow well in a variety of moist soils with moderately good drainage. Pruning is rarely necessary except to remove dead or damaged wood. These are ideal trees for home orchards and landscapes as well as natural areas and native woodland gardens.
This can be a difficult tree to propagate. The seeds require a long period of cool stratification (extended exposure to cool, moist conditions) before they will germinate. Stem cuttings have proven mostly unsuccessful though pawpaw grafts well. This species tends to produce many root suckers, but they do not transplant well. All pawpaws require gentle handling and a long period of adjustment to survive transplanting.
Pawpaw leaves, seeds and bark contain complex chemical substances, which are under investigation for anticancer drugs as well as insecticidal uses. The leaves are the larval food for zebra swallowtail butterflies and pawpaw sphinx moths. In fact, the chemicals help the insects against predation.
