Thursday, January 12, 2012

Ironwood's toxins help it outlive termites

Today's question: Reprinted from The Arizona Republic
I do woodworking and use native Arizona ironwood sometimes because it is similar to rosewood and quite beautiful. But it is highly toxic and I must wear a respirator to keep from inhaling the sawdust. What makes it so toxic? Is it safe to burn in a fireplace?
Ironwood is pretty interesting stuff. Did you know it's a legume? I didn't until I started looking into this question. Being a legume means it enriches the soil with nitrogen.
Anyway, about its toxicity. Do want to know how toxic it is? It is so toxic that it takes 1,600 years for a hunk of ironwood to decompose because the termites and other critters that might chew it up can't handle the chemicals.
I couldn't find a full list of ironwood's toxins, but they seem to mostly be toxic alkaloids that probably are hard to spell.
On top of being toxic the leaves of some varieties are hallucinogenic.
As for burning it in your fireplace, that doesn't sound like a good idea.
Ironwood is just about the heaviest, densest wood you can find, so much so that it doesn't float in water.
On the Sonoran desert it serves as a nurse plant. That means its foliage protects the seedling and sapling of some other plants from extreme heat or cold and from solar radiation. The oldest known ironwood was determined to be around 800 years old, but their average age is about 200 years.
Ironwood may grow as a multi-armed shrub or as a tree. The largest known ironwood tree grows near Gila Bend. It is about 49 feet tall and 14.2 feet around, according to the Arizona Register of Big Trees.
Reach Thompson at or 602-444-8612.

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