Black Heartwood and Persimmons

Black Heartwood and Persimmons

In the dead of winter, it can be hard to come up with good Plant Stories. Staring at my computer screen waiting for inspiration, I realized that I have a subject staring me right in the face, and I’m wearing it. I was given a lovely wooden bracelet for Christmas and found out later from my friend Maggie, who made it, that the wooden beads are made of ebony. I knew that ebony is an exotic and somewhat controversial wood, but I didn’t actually know what kind of plant ebony comes from. This turns out not to be surprising, as the ebony family (Ebenaceae) is mostly found in tropical Southeast Asia and Africa. Although members of this family are a major component of forests there, only a few species are native to North America and none of them reach as far north as Canada. A few neat things about the Ebenaceae: being in the order Ericales, they are relatively closely related to a bunch of familiar plants like kiwifruit, tea, Brazil nuts and blueberries. Also, nearly all of the approximately 500 species in the family have separate boy plants (producing pollen-bearing flowers) and girl plants (producing seed/fruit-bearing flowers). Botanically speaking, plants like this are called dioecious (“di”=2, “oikos”=dwelling, so “two houses” [ie. one male and one female]) and other examples include hollywillows and Cannabis. Another curiosity of the Ebenaceae is that most of its species are in one enormous genus, Diospyros, with just a handful of species in two or three other genera. One source I found made the lofty claim that Diospyros is “about the most diverse genus in West Malaysia”, an ecoregion already known for its vast biological diversity.

Ebony: Dark Wood with a Darker Future?

Cross-section of raw ebony wood: source

Cross-section of raw ebony wood: source

It turns out that another characteristic, probably the most obvious one, of members of the Ebenaceae is the production and concentration of naphthoquinones in their tissues, which turn them black. So pretty much all the species in the ebony family can have black bark, black wood, black roots and even the leaves sometimes turn black when the dry up and fall off. This means that there is no specific “ebony plant”; rather, any of the 500 or so species in the ebony family can produce the distinctive dark wood. Here is where ebony’s story starts to get a bit scary: you may have heard that ebony products are questionable in terms of sustainable harvest, well it appears that at least 3 species that produce ebony are on the IUCN redlist of threatened species and that many other ebony producing species are poorly documented, meaning they could be on the brink of extinction, or they could be doing just fine, we really have no idea. The scary part is that since wood from all of the Ebenaceae is black and dense, it is very hard to know what you have when you are looking at a particular object made of ebony. My bracelet, for example, could be made from an endangered species, or maybe not. To make matters worse, whole species of ebony producing plants could be over-harvested to extinction and, as far as the international trade marked would observe, there would still be plenty of ebony to be had. Worse still, members of this family are characteristically slow-growing so post-harvest regeneration or anything like “ebony farming” would be very slow going, indeed. Unfortunately, people’s appetite for the luxurious dark wood has turned out to be more than these plants can keep up with. So, if we want to enjoy a sustainable crop from members of the Ebenaceae, maybe we would be better off choosing something that grows back every year or two…. like a fruit!

Tree Candy: Persimmons

A full harvest on one tree of Diospyros kaki (Japanese persimmon); source

A full harvest on one tree of Diospyros kaki (Japanese persimmon); source

The fruit type in the ebony family is technically a berry, though many ebony fruits are pulpy or fibrous on the inside. Other species have plump, juicy fruits that, although astringent from tannins when unripe, are sweet and delectable once they ripen. These fruits are called persimmons, and they occur in a small group of species within Diospyros that also happens to be the most tolerant to temperate climates. There are a few species commonly cultivated in China, and one in North America (Diospyros virginiana), although it is usually only used as a hardy rootstock for grafting the Asian species. If you haven’t tried a persimmon, by the way, you are in for quite a treat. When soft and ripe they have a texture like jelly-candy and a sweet-and-sour taste that is pretty much as good as it gets. Although the plants won’t produce fruit until they’re about 10 years old, when they do, it is an orange bounty. With traits like these, it’s odd to me that persimmons aren’t up there with apples and grapes as quintessential “staple” fruits.

Orange is the New Black

The delectable flesh of the Japanese persimmon fruit; source

The delectable flesh of the Japanese persimmon fruit; source

Call me crazy, but I think there may be a simple solution to the problem facing the Ebenaceae. Since persimmon trees produce dark wood like all the members of the ebony family, maybe we just need to swap our voracious appetite for ebony with our mild admiration of persimmons. We should be gorging ourselves on the orange fruit, requiring plantations of native Diospyros both in Southeast Asia and in North America. When the trees get old enough, cultivators could harvest them for ebony and perhaps we would have enough ebony to keep the luxury wood market satisfied. A tidy story, anyway, but I’m sure it’s easier said than done. For my part, I’m off to find some Diospyros virginiana seeds: I’ll be rolling in persimmon jam just a short decade from now, and in another decade or two after that I’ll have all the exotic black wood I could ask for.

By the way, if anyone is interested in Maggie’s ebony bracelets or other beautiful jewelry, it can be found here

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