Olneya tesota

Taxobox
name = "Olneya tesota"

---

image_width = 255 px
regnum = Plantae
divisio = Magnoliophyta
classis = Magnoliopsida
ordo = Fabales
familia = Fabaceae
subfamilia = Faboideae
genus = "Olneya"
species = "O. tesota"
binomial = "Olneya tesota"
binomial_authority = A. Gray

"Olneya tesota" is a perennial flowering tree of the Fabaceae family, legumes (peas, beans, etc), which is commonly known as Ironwood or Desert Ironwood. It is the only species in the monotypic genus "Olneya". This tree is part of the western Sonoran Desert complex in the Southwestern United States, which includes flora such as palo verde, saguaro, ocotillo, brittlebush, creosote bush, and mesquite.

Description

The Desert Ironwood grows as a bush or tree and reaches heights of about convert|10|m|ft|0, and average diameters of about convert|60|cm|in|0; in exceptional sites in larger protected washes, greater height and more massive.

In younger trees, the bark is gray, shiny, and smooth; in older trees the bark is broken open. The tree is an evergreen plant, but can lose its leaves if temperatures fall below 2 deg C (37 deg F). In continual drought conditions leaves will be lost.

Leaves are bluish-green and pinnate compound. Leaves are arranged on a petiole, convert|6|in|cm|0 long, with 6-9 leaflets, each being 0.7 to convert|2.5|cm|in|0. At the base of each pinnate leaf petiole grow two thorns, about 1 cm long.

Bloom time occurs in late April/May to June. Flowers are of 5 unequal petals, in colors of medium purple, magenta-red, or also white to pale pink. Seedpods are 5-8 cm (2-4 in) long.

Range and location

The Desert Ironwood, "Olneya" is native in the southwestern United States in the western and southern Sonoran Desert, and is partially an indicator species of that desert. It ranges to Baja California Sur, as well as the north Baja California, and is only east of the Baja Peninsula cordillera ranges, on the Gulf of California-(Sea of Cortez) side. It ranges northwest into the Colorado Desert-(a part of the Sonoran Desert), of Southern California, is in western and southern Arizona, and Sonora state Mexico. Its range in Sonora is west of the Sierra Madre Occidental cordillera and in the south, approaches the northern border of northern Sinaloa state. "Olneya" does not range into the higher elevation, colder, southeast of Arizona Sonoran Desert region of the sky islands of the Madrean Sky Islands region.

Ironwood Forest National Monument in southern Arizona is named for "Olneya tesota".

Use

Olneya ironwood is very hard and heavy. Its density is greater than water and thus sinks; it does not float downstream in washes, and must be moved by current motion. One popular usage for the wood is for knife handles, since its hardness, beautiful grain, and coloring is ideal.

Workability

Due to the high hardness of the wood, processing wood is difficult, and requires the hacksaw, or other metal-working type tools. Final treatment of the wood with solutions can be difficult, due to the desert ironwood's high density.

External links

* [http://ucjeps.berkeley.edu/cgi-bin/get_JM_treatment.pl?3691,4151,4152 Jepson Manual Treatment]
* [http://plants.usda.gov/java/profile?symbol=OLTE USDA Plants Profile]
* [http://calphotos.berkeley.edu/cgi/img_query?query_src=photos_index&where-taxon=Olneya+tesota Photo gallery]