The desert ironwood tree (Olneya tesota) is a legume, like peas and beans. It's an extremely hardy tree, able to withstand blistering heat and long periods of severe drought as well as the occasional sub-freezing temperatures of the Sonoran desert. Individual trees may live 800 to 1,200 years, though precise dating can be difficult because growth and growth rings may essentially stop when there is insufficient water.
Native only to the Sonoran desert of the southwest United States and parts of northern Mexico, the ironwood is a mainstay of desert life. The trees often provide shade and protection for saguaro and other cactus seedlings, as well as nesting for various birds and mammals.
The ironwood is an impressive feature of the open desert, with dark, slightly bluish foliage. Large individuals may reach 45 feet in height, with thick, gnarled trunks and multiple branches.
Ironwood is so named because the wood is dense and extremely hard. It is too heavy to float in water, and must be moved by strong current in storm-flooded washes.
This is the normally dry-as-a-bone Hassayampa River in Wickenburg, AZ, taken February 2005. We saw plenty of old ironwood trees in this flood, along with several cars and two houses.
Like all trees, ironwood trees contain heartwood and sapwood. As the tree matures, the older, inner heartwood turns dark, almost black; the outer sapwood is lighter, like oak or maple. When the tree dies or a limb is cut, the sapwood is eaten away by borer worms, but the heartwood remains long after.
This is the remains of a long-dead ironwood out in the desert near Hummingbird Springs, west of Phoenix, AZ.
Though traditionally used for firewood and making charcoal, the dead heartwood is now used almost exclusively for carving. The craft was originated by the Seri Indians in Mexico; the tree is now a protected species in Mexico.
But it is still plentiful in our Arizona desert.
In the late 1990s, when the huge Sundance development was being constructed in the desert north of Buckeye, Arizona, my husband and I got permission from the contractors to reclaim a tiny portion of the ironwood timber that was being bulldozed to make way for tacky little houses, golf courses, and shopping centers. Almost all of this was live ironwood, with both the heartwood and lighter sapwood. The contrast is dramatic, and it can be made even more so with the inclusion of fillers.
Ironwood tends to be full of cracks and fissures, which can be left as is when using the wood for crafts, or filled with either a decorative material such as Inlace (c) or with a simple mixture of epoxy and . . . something else. We used laboriously hand-crushed natural chrysocolla -- a turquoise-colored quartz-like material -- mixed with epoxy to fill the gaps in the wood before making various things with it.
The living heartwood is very high in silica -- the same silicon dioxide as common quartz -- which gives the dark wood a golden shimmer very much like tiger's eye stone.
When the heartwood is dead, it turns darker and loses some of this shimmer.
These ^^ are old pictures, taken 2003-2005. In the one immediately above, you can see the contrasts between light sapwood and dark heartwood, the golden shimmer of mature heartwood, and the darkening when the heartwood is dead.
When I moved from Buckeye to Apache Junction in 2006, I was delighted to have several trees on the property. But I didn't have an ironwood tree. So I bought a small one at the Boyce Thompson Arboretum's plant sale. It wasn't very big.
A certain someone didn't like it, thought it was ugly, and probably secretly hoped it would die. Since I'm not very good with plants, there was a pretty good chance it wouldn't survive.
But it did. And it grew.
And finally, this year for the first time it had some flowers. Not very many, but it had a few.
I was deliriously excited that my ironwood tree had some flowers! A mature tree out in the desert will be a veritable cloud of lavender, though the tiny individual flowers are a combination of very pale pink and maroon.
My tree had grown from its modest beginning.
But it had grown kind of unruly. Ironwoods have horrible, horrible thorns, which makes trimming them just plain dangerous.
That certain someone flat out refused to touch it, and I never seemed to have time. So last week, when I was laid up with my bad back and the yard needed to be taken care of ahead of the studio tour, we simply had to have the landscape guys come in and do the job properly. And they trimmed my tree.
This is the view basically from my front porch across the yard to the neighbor's house. The low stone wall in the background edges my driveway. The driveway actually follows the course of a small tributary wash that comes down off the mountain, so when we get a heavy rain, the driveway can flood dramatically. This morning, though, everything is dry and sunny. And I'm so proud of my tree!
When I came in from taking the photos of the tree, I noticed that my little photo "studio" in the family room was in full sun, so I grabbed the ironwood box pictured above and took another photo of it that better shows the chrysocolla inlay. One of these days I'm going to get back to the woodworking. I still have a whole pile of that ironwood we salvaged from the construction crew. . . . .