Trees Of Oaxaca - the "Guage" tree

OK, so this post is not for everybody. In fact, maybe it's just for Mike Larson, my self-proclaimed plant geek friend. And maybe for Hannah, my only kid who has even pretended to take an interest in trees.

Being a bit of an aspiring plant geek myself, and recognizing almost none of the trees here in Oaxaca, I am making it a mission of mine to learn to identify at least some of the more common trees here. There are lots of trees that look like legumes, with their compound leaves and beans of one sort or another. They remind me a bit of the honey locust and black locust trees you see back in Minnesota.

But whereas in Minnesota you might see one or two legumes among the vast majority of maples, oaks, birch and pines, here in Oaxaca the legumes are in the majority. I think that is because the soil here is deficient in nitrogen. I further suspect that this is caused, or at least exacerbated, by centuries of agriculture (the indigenous Zapotecs began practicing agriculture in the Oaxaca Vally in 1500BC). Nitrogen, abundant in the atmosphere, is the number one limiting factor in most plants (it's the "N" in N-P-K fertilizer labeling). Legumes are able to pull nitrogen out of the air and fix it in the soil for their own use, and when they drop leaves, slough off roots or die, they leave it behind for other plants. A plant that can fix nitrogen has a distinct advantage here over trees that require nitrogen to already be in the ground.

The Guage Tree (Leucaena leucocephala) - common names include wild tamarind, white leadtree, jumbay, faux acacia, faux mimosa, white popinac.

In Sarah's post from 8/21/14, "How Do You Pronounce Oaxaca?", she makes mention of that Oaxaca (a derivation of "Guaxaca") takes it's name from the Guage tree (pronounced "GWAH-hey"). So this became the first tree that I set out to identify. Luckly, many of them are in bloom right now, with the white spherical flowers (at left) which makes them a LOT easier to identify.

Turns out this tree has quite a story. Native to Guatemala and southern Mexico, it has been introduced around the globe as a kind of miracle tree - a long-lived, tough perennial legume with a deep tap root that breaks through hard-pan subsoils. It also produces edible shoots, leaves and seeds for people and for limited use with livestock. It's wood is used for charcoal, furniture and paper. But it also spreads quickly, so it is considered by some an invasive. And it blooms year-round, so it yields beans year-round as well.

I'll post more about the local plants as I learn more about them. Though I know it's not for everybody, I know at least one or two of you will be interested to hear more. :-)