The desert around Tucson is now very colorful with an unusually profuse blooming of palo verde trees (see Palo Verde Trees Will Turn the Desert Golden). That will soon be supplemented by the white and lavender flowers of the desert ironwood tree.

The desert ironwood (Olneya tesota) is a hardy tree that grows up to 35 feet tall. Its twice pinnate leaves hide a pair of sharp, curved spines. According to the Arizona-Sonora Desert Museum, “The nearly evergreen foliage is dense and deep green in wet years, sparser and gray-green during drought. In the extremely arid islands in the central Gulf of California the trees become completely leafless at times. Mature trees also shed their leaves a few weeks before flowering in May, then re-leaf when the summer rains come; only limbs that will flower drop foliage.”

The trees don’t bloom every year, perhaps two out of five. The flowers range from white to deep lavender, often becoming darker with age. The trees bloom for only 10 to 18 days.

The desert ironwood ranges throughout the Sonoran Desert but is restricted to areas where the temperature does not regularly fall below about 20 °F. In very dry areas, the trees are restricted to washes.

The desert ironwood produces edible beans that are high in protein and taste like peanuts. There is, however, a caveat: the beans are mildly toxic and should not be eaten raw in large quantities. The Seri Indians prepared the beans by twice boiling them and discarding the water in between. The flowers are also edible. (See video below for information on harvesting and preparation.) Many animals eat the beans without apparent ill effect.

Desert ironwood trees grow slowly, but live long, 300 years or more. Age determination is difficult because tree growth rings are incomplete or even missing. The wood is so dense, it will not float in water. The density makes the desert ironwood a favorite of wood carvers.

The wood is essentially non-biodegradable. Dead trees can stand for 1,000 years. They do not rot due to toxic chemicals in the dark heartwood. It may take centuries for dead ironwoods to physically degrade. Some dead ironwoods have been carbon-dated at 1,600 years old.

Ironwood makes excellent firewood which burns long and hot. In the past, the trees were almost extirpated in parts of Sonora from use as firewood and harvesting for carving. Such practice is now illegal; the trees are protected in both Arizona and Sonora.

There are desert ironwood trees flowering now along Gates Pass and along Kinney Road on the way to the Arizona-Sonora Desert Museum. Also of course, the trees occur in Ironwood Forest National Monument near the Silver Bell Mine between Tucson and Marana. (See that link for many photographs.)

See this 5-minute video from Desert Harvesters on harvesting the flowers and beans for food:

See also:

Edible Desert Plants – Barrel Cactus Fruit

Agave, a plant of many uses

Brittlebush and chewing gum

Can You Get Potable Water From a Cactus?

Mesquite Trees Provide Food and a Pharmacy

Yuccas provide food, fiber, and soap

The Arizona-Sonoran Desert region has more wild edible plants than anywhere else on the planet according to ethnobotanists. We have cactus fruit, beans from mesquites and palo verde trees, yuccas, agaves, and nut trees, to name just a few edible plants.

Today, I will focus on the barrel cactus. Most cacti bloom in the spring. The barrel cacti bloom and set fruit in the summer. All cactus fruit is edible, none are poisonous, but not all are palatable. The best cactus tasting fruit comes from the saguaro, prickly pear, and barrel cactus.

There are six species of barrel cactus in the region. The most common in the Tucson area are Ferocactus wislizeni, the Fishhook barrel, and Ferocactus emoryi, Coville barrel. The Fishhook commonly grows 2- to 4 feet high, but some can reach 10 feet. Coville is generally 1- to 4 feet. The flower color of Coville is bright red; the Fishhook flower is usually orange, but can also be yellow or red.

The spines of the Fishhook are strongly-hooked and surrounded by several radial spines. The main central spine of the Coville is usually red, flattened and hooked. The few radial spines are relatively wide.

The fruit starts out green, but gradually ripens to yellow. Together with the withered flower, the fruit looks like a miniature pineapple. Because the fruit is relatively dry, it does not rot away like the fruits of saguaros and prickly pears. It is common to have the fruit remain on the plant for a year – until something picks it off.

I especially like barrel cactus fruit because it is the only one without spines; it can be picked and eaten raw right off the plant; both the flesh and the seeds inside can be eaten raw or cooked. The flesh is slightly mucilaginous (slimy like okra). The taste is tart; somewhere between lemon and kiwi fruit. The seeds may be separated and ground to a mush. If you pick a fruit that has been on the cactus for sometime, check for insects unless you don’t mind the extra protein. The flower buds can be eaten also. The buds were often boiled and used like cabbage by native tribes.

Cactus fruit in general is rich in vitamin A and vitamin C. There is clinical evidence that the juice of the fruit of prickly pears lowers blood cholesterol. This may be a characteristic of most cactus fruit, but only prickly pears have been tested so far. If you have a barrel cactus in the yard, and the fruit is yellow, try taking a bite, they are good.

You may notice that barrel cacti frequently lean in one direction – toward the south. This is a reliable indicator of direction in the desert. They lean south so the top can get the most sunlight.

It is reported that Seri Indians sometimes used the Fishhook barrel for emergency water. However, drinking the juice on an empty stomach often causes diarrhea, and some Seri report pain in their bones if they walk a long distance after drinking the juice. The Seri called the Coville, “barrel that kills” because eating the flesh of the cactus (not the fruit) causes nausea, diarrhea, and temporary paralysis, but the pulp can be used as an external analgesic.

Enjoy the fruit of the desert.

Reference: A Natural History of the Sonoran Desert, Arizona-Sonora Desert Museum.