Thursday, January 19, 2012

Kentucky Coffee Tree

A fine specimen of a Kentucky coffee tree, Gymnocladus dioicus, towers skyward at Columbus, Ohio's sprawling Green Lawn Cemetery. The 360-acre Green Lawn - 2nd largest cemetery in the state! - is a virtual arboretum, with some 90% of the Buckeye State's native tree species in residence. Many of the natives, such as this coffee tree, were not planted; rather they are part of the indigenous flora that has been incidentally conserved by the establishment of the cemetery.

Of all of the trees at Green Lawn, the Kentucky coffee trees may be my favorites. They may seem a bit homely, perhaps, especially when contrasted with the stately columnar trunks of nearby tulip trees, or the soft elegance of eastern hemlocks. In the company of the runway model trees, the coffee trees might be considered ugly ducklings but to me that is part of their allure.

If you were to paint the quintessential spooky Halloween scene - full moon in the corner, haunted house in the backdrop, bat winging by, owl glaring from a tree - it's the Kentucky coffee tree that you'll want to star as the centerpiece. Its wildly contorted branches twist and jag crazily, and the thick stubby twigs create the effect of ill-kept witch's brooms.

The trunk is broken into long furrows, as if tectonic plates of bark have collided and ruptured against one another. Like the rest of the tree, even the bark has a messy charm to it.

The long persistent seed pods instantly reveal the coffee tree's allegiance to the Fabaceae: the bean family. Stunted and stubby like the branches they hang from, coffee tree pods suggest fat little locust seed pods. You'll only find the fruit adorning female trees, though - the specific epithet of this plant, Gymnocladus dioicus, means = diocecious. Dioecious plants have separate male and female plants, so if you've got a Kentucky coffee tree that never produces fruit, it's likely a male.

Your blogger took the liberty of plucking a pod from the Kentucky coffee tree, and it protested not a bit.

Split open, we can see the thick greenish-yellow pulp that the fingernail-sized seeds nest in. The tree's common name stems from the sometimes use of the seeds as a coffee substitute, at least in days gone by. I would NOT recommend brewing up drink from this stuff, though - the seeds, leaves, and other parts of this tree are at least mildly toxic and you'll get more bang than you probably wanted.

Ohio Division of Forestry forester Brian Riley holds a Kentucky coffee tree leaf. I took this photo at Green Lawn several summers ago, and if you visit these trees during leafout, you'll be rewarded by the spectacle of the largest leaf of any Ohio plant. The whole assemblage in Brian's hand is just one very large leaf, and in botanicospeak it is termed twice pinnate. Each unit is a leaflet, and collectively it is all of those little leaflets that comprise the leaf in toto.

Kentucky coffee trees are not especially common, and never form dominant stands, at least insofar as I have seen. They prefer alkaline soils and are most likely found where limestone beds jut near the earth's surface in central and western Ohio. Green Lawn Cemetery is without doubt one of the best places to easily find coffee trees and admire their rather homely charms.

11 comments:

Anonymous said...

Next time you are at Old Reid Park in Springfield checking the ponds for ducks, look to the left toward the tennis courts. There is a grove of Kentucky Coffeetrees in the lawn there. There are 3 or 4 females and a few males. I collect seeds every year. Otherwise the pods fall and get crushed by mowers. Where are the mastodons when you need them?
Brian

Auralee said...

There are Kentucky Coffee Trees along the autotour at Dawes Arboretum, right before the turn on the way to the observation tower. Every time we pass the sign that announces them, I remark, "I didn't know we were in Kentucky." Ans my husband answers with a sigh.

Anonymous said...

I have seen these pods hanging on trees and wondered what species of tree this was. Thanks for helping me identify this wonderful tree. Why do people collect the seeds and what do they do with them? As always a wonderful article and I enjoy reading your posts.

Anonymous said...

The seeds are for growing more coffetrees of course. I collect the pods in March as they fall, so they've already had the required cold period. I use a file to weaken the tough seed coat, soak them in warm water for a few hours; and they swell up with water and are ready to stick in a pot to sprout. I pass them on to my father-in-law who has a little nursery operation. He grows a few every year, and trades seed with other growers sometimes.

Brian

Cheryl Whipple said...

Hummingbirds like their blossoms too. I remember seeing hummingbirds around Kentucky coffee tree at the BSBO banding station many springs ago.

bluejay85 said...

hello

krustukles said...

Thanks so much for this post! I just found one of these trees in downtown Toronto and was quite puzzled by it until I discovered your very helpful post. Appreciate you sharing your knowledge with the rest of us. :)

Xylonjay said...

I believe that we have discovered a small stand of these odd trees near the Como Park Zoo/Observatory in St. Paul, MN. We could not figure out what were as we had never seen them in all of our lives living here.

Xylonjay said...

I believe that we have discovered a small stand of these odd trees near the Como Park Zoo/Observatory in St. Paul, MN. We could not figure out what were as we had never seen them in all of our lives living here.

Anonymous said...

we have one (left out of two) of these in our yard I was told some previous homeowner actually planted these at a time when the people were trying to outdo one another for the distinction of having the most unusual tree in their yard. I wish I could blink and let someone who admires it have it -- the nasty beans drive my husband nuts. they are rough on the blades of the mower and if you get hit by one of them, it HURTS. the wood doesn't burn worth a darn, it's tough to cut, branches get blown down quite frequently. The only thing I like about it is there's a red-headed woodpecker who seems to like it....so much for differing opinions, I guess.

Judy W said...

Fifty years ago I played in a small stand of towering trees in a city park in Wapakoneta, OH. t wasn't until 20 years ago when we moved into and old home near downtown that I found out what those trees were/are. They're still there next to the new waterpark. Our old home is next door to HUGE specimen that I'm told is possibly the oldest in the county. The trunk is at least 36" across. Being close to downtown the yards are very, very small. I have a love/hate relationship with this tree due to the debris. Thankfully, no seed pods. The property is currently for sale, so the fate of this tree will be up to the new owners. What has saved it in the past has been the removal cost. How can I estimate the age of this tree?