| Boiling Point No. 17 - December 1988 |
"The Mesquite is the only shrub that can reach the water table here with its roots. But a mesquite seedling must send its roots down 30 feet or more through dry sand before it reaches the water. How then does it get established? This is one of the unsolved mysteries of the desert".
The mesquite seeds theselves are of some help. They rarely grow if merely planted in the soil. But if the seedpods are eaten by animals, whole seeds that pass through the digestive tract sprout readily. Digestive juices erode the tough seed coat, allowing moisture to penetrate and start germination. When passed by the animal, the seeds have a supply of manure to aid the seedling's initial growth. Moreover, that growth is concentrated in a taproot - little growth occurs above ground until the taproot has found groundwater 30 feet or more feet below.
In other deserts local rains may help, but in Death Valley a rainfall of 1.35 inches spread out over a year's time would be negligible. How the seedlings survive there while taproots grow 30 feet or more in dry sand is the unsolved mystery. Even in other deserts the feat is remarkable, especially since some mesquite roots go down 200 feet to find water ! The Sonoran Desert Museum in Tucson, Arizona, tells of a mine where mesquite roots were found at a depth of 175 feet. But once the roots hit water, the plant above ground takes off. Where the underground supply is plentiful, the mesquite tree may reach over 40 feet in height and 3 or 4 feet in diameter. Other desert plants may wither and die during desert droughts, but the mesquite stays green. It deep roots drink from underground waters fed by the rains and snows of distant mountains. It also has a web of surface roots extending out from its base, and these pick up moisture from passing showers. But it is the deep-probing taproots that locate the undergound reservoirs so efficiently that well diggers sink their wells nearby.
The Docent Note Book for the Sonoran Desert Museum offers this information as to the mesquite's usefulness:
"At one time it was of great value as a timber tree in the desert. It is still used for fence posts, charcoal and firewood. (It is slow-burning and produces a hot fire with good flavour). Violin bows are sometimes made from the root wood The inner bark furnished both Indians and settlers with materials for basketry, coarse fabrics, and medicine to treat a variety of disorders".
But there is another use for the mesquite tree or shrub. From spring to early summer, long, fat, yellow blooms hang from the tree like huge fuzzy caterpillars. And they are the source that adds sweetness to the mystery of the mesquite tree's l if e. Ralph Lusby is a beekeeper who keeps hives where the mesquite flourishes in the Arizona desert.
"Near dry streambeds mesquite trees that get plenty of water give 3 full blooms in a season. I've tasted lots of honey in my life but mesquite is by far the best. My major mesquite honey flow is from April 20 to June 10 on the average. l love my bees. They take care of me and l take care of them".