Peculiar Pittsburgh

Monkey balls, banana apples, and buckeyes: Answering all your Pittsburgh tree questions

You can’t stump these tree experts.

Branching out to answer all of your tree questions.

Branching out to answer all of your tree questions.

Jennifer C. / Flickr
Rossilynne Culgan

It turns out monkey ball trees are overwh-elm-ingly poplar.

Puns aside, we found out that Pittsburghers are very into learning about our region’s unique trees. Questions and comments about monkey ball trees poured in through Peculiar Pittsburgh, where you can ask your own questions about trees — or any other Pittsburgh mysteries — and we try to solve them.

Some readers shared monkey ball memories with us, like one who said, “There is a Mt. Lebanon street called Osage Road. We used to roll the monkey balls under passing cars!”

For Anthony Boff, it seems we answered a long-standing question: “Great article. I was wondering why our Osage orange trees were lined up in a row. Our house was built in 1820 in Bethel Park.”

And yet another reader told us that: “The oil from the seeds of the ‘monkey ball’ is sold by Limelife by Alcone. It is a fantastic, all natural skin moisturizer.” Yup, it appears to be a real thing, though we can’t vouch for it ourselves.

Many others shared their arboreal wonderings about monkey balls and other trees, so we asked experts to speak for the trees: Bonnie Isaac, collection manager of botany at Carnegie Museum of Natural History, and Joe Stavish, community education coordinator at Tree Pittsburgh. Here’s what they say:

Is the inside of a monkey ball actually latex? If so, can they be used for such a purpose? If not, what can be done with them?

Turns out, about 10 percent of plants produce latex, but that doesn’t mean it’s a usable product, Isaac explained.

“Most plants either don’t produce enough latex or produce some form of latex that requires a lot more processing, thus it is not economically feasible to use,” she said. “Latex is produced by plants to protect them from being eaten. Plant-eating insects tend to avoid plants that produce latex.”

Though researches have looked into plant latex to make products, monkey balls haven’t been used in that way — yet, Stavish said.

“That’s sometimes how we get new uses for nature products: There might be some student at CMU that says, ‘Hey, I could look into that,'” he said.

Do monkey balls keep out moisture, in addition to (maybe) being a natural bug repellant?

Probably not.

“Osage orange fruits (monkey balls) are about 80 percent water,” Isaac said. “I don’t see how these would keep moisture out.”

Stavish agreed, noting that they quickly decompose.

“I think what you’re going to have is a big mess of fruit flies and rotten mush,” he said.

Are monkey ball trees related to the Caribbean bread fruit trees?


“Breadfruit trees (Artocarpus altilis) and monkey ball trees (Maclura pomifera) are in the same family. The family Moraceae also contains figs and mulberries,” Isaac explained.

We used to have an apple tree on our farm that we called a banana apple tree, because the apple had a banana taste to it. What was it?

First of all, can we try one of these?

Second, Isaac said, there is indeed a variety of apple called the Winter Banana Apple, which originated from the state of Indiana around 1875. It was introduced commercially in 1890.

“The Winter Banana apple is one of the few apple varieties that is self-fertile. Most apples need another variety of apple to pollinate them,” she said. “Winter Banana Apples usually ripen around late October.”

Apples, except for crabapples, were not native to North America, meaning the apples we’re familiar with today like Macintosh, Honeycrisp, or Red Delicious were brought over or created, Stavish explained. The banana apple was likely an heirloom variety created years ago and lost to time.

Can you tell me about the “Topi” tree?

The question-asker likely means “Toby” trees, Stavish hypothesized.

The “Toby” tree is a yinzer word for the Northern and Southern Catalpa tree, known for their giant bean pods and heart-shaped leaves.

“Catalpa” is a Native American word from the Creek tribe, meaning “head with wings,” a reference to the flower petal.

People used to plant them at their homes, but they’re not so common anymore. The trees grow well by the water where they attract black-and-gold caterpillars.

Some call these trees “cigar” trees, though Stavish does not recommend actually smoking these bean pods, as it will make you sick.

Their name is a Pittsburghese phrase, Stavish said, but “there’s nothing that explains why people call them Toby trees.”

Where are all the buckeye trees? I wanted to show my grandson how we made rings and necklaces from them.

Buckeyes are closely related to horse chestnut trees, which can be found several places around Pittsburgh, such as Schenley Park and Highland Park, Isaac said.

“You can also find buckeye trees in the woods in many areas of southwestern Pennsylvania,” she added. “There are two species of buckeyes that are native to southwest Pennsylvania, Yellow Buckeye (Aesculus flava) and Ohio Buckeye (Aesculus glabra).”

The trees most people grew up calling “buckeye” are likely “horse chestnut,” Stavish said. They look similar, except for the pod they grow in. The buckeyes and the horse chestnut are poisonous to humans and are not edible, Stavish said.

Actual chestnuts (American Chestnuts or Chinese Chestnuts) — the kind for roasting on an open fire — are different, he said.

Can you tell me more about our black walnut trees?

Black walnut trees (Juglans nigra) are closely related to the English walnuts we buy in grocery stores, but black walnuts have a much tougher shell that is very difficult to crack, Isaac said. Cracking black walnuts open is also very time consuming.

“You can buy cracked black walnuts, but due to the difficulty of cracking them they are seldom in large pieces and are quite expensive compared to English walnuts. Black walnuts also have a much stronger flavor. There are specialty nut crackers made just for cracking black walnuts and hickory nuts (which are in the same family as walnuts),” she added.

Plus, Stavish said, people consider them a “messy” tree, given their husk that rots and color that stains.

“The average person just lost favor (for the tree) because of the mess that the leaves and the nuts create,” he said.

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