Have you ever eaten a Pawpaw? No, I’m not asking you if you have a history of elderly cannibalism. I’m talking about North America’s largest tree fruit, the Pawpaw Asimina triloba. Have you ever had one?
If you haven’t, I’m not that surprised. Even though this species of tree and its fruit can be found growing in 26 states from New York south to the Florida panhandle, and west to Nebraska and Texas, it is not very common in the wild, especially fruit-bearing populations.
There are some interesting reasons why this is. For one, Pawpaws require more than one genetic variety for pollination and the resulting fruit set. As Pawpaws are a clonal tree species and any one patch is likely to be identical genetically, for successful pollination to occur, pollen must be delivered from a completely different individual plant with different genetics.
Another reason you may have never tried a Pawpaw is that their fruits, lumpy and ugly with a green skin, cannot be picked early and artificially ripened. In fact, you don’t pick Pawpaws. You pick them up off the ground just like the old song says. If they are on the tree, they are not ripe and will not continue to ripen after being picked. Pawpaws also have a short shelf-life and will rot long before they can be shipped to a store. You can sometimes find them for sale at a farmer’s market if you’re lucky.
If you know where to get Pawpaws, you’re lucky indeed. Inside of that lumpy green fruit are large brown seeds that you don’t eat. Surrounding those seeds is flesh that tastes something like banana custard combined with a mango. They are delicious!
Probably the oddest reason that Pawpaw trees and their delicious fruits aren’t as widespread as they once were is found in a long tale about how old the trees are and how long they’ve been growing on this planet. The animals that used to eat the ripe fruit whole and then help to spread the seeds through digestion were the Giant Sloth and the Mastodon of the Pleistocene Era, which went extinct as recently as 11,000 years ago. That’s a long time.
Due to the loss of these large animals, Pawpaws are considered an ecological anachronism. Other ecological anachronistic plant species around us include the Honey-locust Gleditsia triacanthos, whose large, sweet bean pods were also eaten by Ice Age Sloths and Mastodons, leading this tree species to develop large thorns. The thorns of Haw Trees Crataegus spp. and the Devil’s Walking Stick Aralia spinosa were also produced to ward off animals that no longer exist. While some modern-day animals do eat the fruits, rarely are they able to consume and spread the seeds without damaging them.
Caterpillars of the Zebra Swallowtail Butterfly Eurytides marcellus have not only figured out how to survive the toxic chemicals in the Pawpaw leaves but also how to use those chemicals to become toxic to predatory birds as adult butterflies.
It is up to us to become the new Giant Sloths and Mastodons if we want to continue to have Pawpaws to eat and Zebra Swallowtail Butterflies to enjoy seeing. Plant Pawpaws in your yard and garden if you have space and the right conditions. There are many named, improved varieties to choose from, with large and sweet fruit. And be sure to go collect Pawpaws if you know where some fruiting patches are. Maybe don’t put ‘em in your pocket, though. They’re mushy when ripe and might stain your britches.
(The Joyful Botanist leads weekly wildflower walks most Fridays and offers consultations and private group tours through Bigelow’s Botanical Excursions. bigelownc@gmail.com.)