Regularity: Regularly occurring
Localities documented in Tropicos sources
United States (North America)
Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.
- SPECIMEN BASED RECORD. Published protolog data. http://www.tropicos.org/Reference/9990002
- Anonymous. 1986. List-Based Rec., Soil Conserv. Serv., U.S.D.A. Database of the U.S.D.A., Beltsville. http://www.tropicos.org/Reference/1103
- Rydberg, P. A. 1924. Fabaceae-Galegeae (pars). 24(4): 201–250. In N. Amer. Fl. New York Botanical Garden, Bronx. http://www.tropicos.org/Reference/1740
- Munz, P. A. & D. D. Keck. 1959. Cal. Fl. 1–1681. University of California Press, Berkeley. http://www.tropicos.org/Reference/1717
- Munz, P. A. 1974. Fl. S. Calif. 1–1086. University of California Press, Berkeley. http://www.tropicos.org/Reference/1719
- Wiggins, I. L. 1980. Leguminosae. 644–711. In I. L. Wiggins Fl. Baja Calif. Stanford University Press, Stanford. http://www.tropicos.org/Reference/71
Sonoran Desert Habitat
This taxon is found in the Sonoran Desert, which comprises much of the state of Sonora, Mexico, most of the southern half of the USA states of Arizona, southeastern California, most of the Baja California peninsula, and the numerous islands of the Gulf of California. Its southern third straddles 30° north latitude and is a horse latitude desert; the rest is rainshadow desert. It is lush in comparison to most other deserts. There is a moderate diversity of faunal organisms present, with 550 distinct vertebrate species having been recorded here.
The visually dominant elements of the landscape are two lifeforms that distinguish the Sonoran Desert from the other North American deserts: legume trees and large columnar cacti. This desert also supports many other organisms, encompassing a rich spectrum of some 2000 species of plants, 550 species of vertebrates, and untolled thousands of invertebrate species.
The Sonoran Desert prominently differs from the other three deserts of North America in having mild winters. Most of the area rarely experiences frost, and the biota are partly tropical in origin. Many of the perennial plants and animals are derived from ancestors in the tropical thorn-scrub to the south, their life cycles attuned to the brief summer rainy season. The winter rains, when ample, support great populations of annuals (which make up nearly half of the plant species). Some of the plants and animals are opportunistic, growing or reproducing after significant rainfall in any season.
Creosote Bush (Larrea divaricata) and White Bursage (Ambrosia dumosa) vegetation characterize the lower Colorado River Valley section of the Sonoran. The Arizona upland section to the north and east is more mesic, resulting in greater species diversity and richness. Lower elevation areas are dominated by dense communities of Creosote Bush and White Bursage, but on slopes and higher portions of bajadas, subtrees such as palo verde (Cercidium floridum, C. microphyllum) and Ironwood (Olneya tesota), saguaros (Carnegiea gigantia), and other tall cacti are abundant. Cresosote Bush (Larrea tridentata) and White Bursage (Ambrosia dumosa) form the scrub that dominates the northwest part of the Sonoran Desert. This association thrives on deep, sandy soils in the flatlands. Where the dunes allow for slight inclination of the slope, species of Mesquite (Prosopis), Cercidium, Ironwood (Olneya tesota), Candalia, Lycium, Prickly-pear (Opuntia), Fouquieria, Burrobush (Hymenoclea) and Acacia are favored. The coastal plains of Sonora are composed of an almost pure Larrea scrub. Away from the Gulf influence in the area surrounding the Pinacate, Encelia farinosa, Larrea tridentata, Olneya, Cercidium, Prosopis, Fouquieria and various cacti species dominate the desert.
Many wildlife species, such as Sonoran Pronghorn Antelope (Antilocapra sonoriensis EN), Desert Bighorn Sheep (Ovis canadensis nelsoni) and the endemic Bailey's Pocket Mouse (Chaetodipus baileyi) use ironwood, cacti species and other vegetation as both shelter from the harsh climate as well as a water supply. Other mammals include predators such as Puma (Felis concolor), Coyote (Canis latrans) and prey such as Black-tailed Jackrabbit (Lepus californicus), and the Round-tailed Ground Squirrel (Spermophilus tereticaudus). Other mammals able to withstand the extreme desert climate of this ecoregion include California Leaf-nosed Bat (Macrotus californicus) and Ring-tailed Cat (Bassariscus astutus).
Three endemic lizards to the Sonoran Desert are: the Coachella Fringe-toed Lizard (Uma inornata EN); the Flat-tail Horned Lizard (Phrynosoma mcallii NT); and the Colorado Desert Fringe-toed Lizard (Uma notata NT); an endemic whiptail is the San Esteban Island Whiptail (Cnemidophorus estebanensis). Non-endemic special status reptiles in the ecoregion include the Desert Tortoise (Gopherus agassizii VU) and the Gila Monster (Heloderma suspectum NT).
There are twenty-four anuran species occurring in the Sonoran Desert, one of which is endemic, the Sonoran Green Toad (Anaxyrus retiformis). Other anurans in the ecoregion are: California Treefrog (Pseudacris cadaverina); Canyon Treefrog (Hyla arenicolor); Lowland Burrowing Frog (Smilisca fodiens); Mexican Treefrog (Smilisca baudinii); Madrean Treefrog (Hyla eximia); Sabinal Frog (Leptodactylus melanonotus); Northwest Mexico Leopard Frog (Lithobates magnaocularis); Brown's Leopard Frog (Lithobates brownorum); Yavapai Leopard Frog (Lithobates yavapaiensis); Mexican Cascade Frog (Lithobates pustulosus); Mexican Leaf Frog (Pachymedusa dacnicolor); Red Spotted Toad (Anaxyrus punctatus); Sinaloa Toad (Incilius mazatlanensis); Sonoran Desert Toad (Incilius alvarius); Eastern Green Toad (Anaxyrus debilis); New Mexico Spadefoot (Spea multiplicata); Great Plains Toad (Anaxyrus cognatus); Couch's Spadefoot Toad (Scaphiopus couchii); Cane Toad (Rhinella marina); Elegant Narrowmouth Toad (Gastrophryne elegans); Little Mexican Toad (Anaxyrus kelloggi); Great Plains Narrowmouth Toad (Gastrophryne olivacea); and Woodhouse's Toad (Anaxyrus woodhousii).
The Sonoran Desert is recognized as an exceptional birding area. Forty-one percent (261 of 622) of all terrestrial bird species found in the USA can be seen here during some season of the year. The Sonoran Desert, together with its eastern neighbor the Chihuahuan Desert, is the richest area in in the USA for birds, particularly hummingbirds. Among the bird species found in the Sonoran Desert are the saguaro-inhabiting Costa's Hummingbird (Calypte costae), Black-tailed Gnatcatcher (Polioptila melanura), Phainopepla (Phainopepla nitens) and Gila Woodpecker (Melanerpes uropygualis). Perhaps the most well-known Sonoran bird is the Greater Roadrunner (Geococcyx californianus), distinguished by its preference for running rather than flying, as it hunts scorpions, tarantulas, rattlesnakes, lizards, and other prey. The Sonoran Desert exhibits two endemic bird species, the highest level of bird endemism in the USA. The Rufous-winged Sparrow (Aimophila carpalis) is rather common in most parts of the Sonoran, but only along the central portion of the Arizona-Mexico border, seen in desert grasses admixed with brush. Rare in extreme southern Arizona along the Mexican border, the endemic Five-striped Sparrow (Aimophila quinquestriata) is predominantly found in canyons on hillsides and slopes among tall, dense scrub.
- C. Michael Hogan, Mark Dimmitt, Arizona-Sonora Desert Museum, World Wildlife Fund. 2013."Gulf of California xeric scrub". Encyclopedia of Earth, National Council for Science and the Environment, Washington DC ed.Mark McGinley.
- Mark A.Dimmitt. Biomes & Communities of the Sonoran Desert, Arizona-Sonoran Desert Museum.
Gulf of California Xeric Scrub
This taxon occurs in the Gulf of California xeric scrub ecoregion, situated along the eastern coastal zone and Gulf of California versant of the Baja Peninsula in Mexico, and is delineated by the spine of the La Giganta Sierra Mountains. This ecoregion, located entirely within the nation of Mexico, is classified within the Deserts and Xeric Scrublands biome. Species richness of plants is high in the ecoregion, but modest for fauna; however, endemism is high in this arid habitat, which receives some of the lowest precipitation in all of Mexico.
Dominant flora species are Creosote Bush (Larrea tridentata) and White Bursage (Ambrosia dumosa); moreover, other plant taxa occurring here include: Arizona Nettle-spurge (Jatropha cinerea), Desert Ironwood (Olneya tesota), Acacia brandegeana, Blue Palo Verde (Cercidium floridum), and Chloroleucon mangense var. leucospermum. Species of more mesic habitats occur on the many oases that are present on the Baja Peninsula: Mexican Fan Palm (Washingtonia robusta), Southern Cattail (Typha domingensis), Common Reed (Phragmites australis) and Date Palm (Phoenix dactylifera). The oases are remnants of more extensive mesic environments that existed in the peninsula in prehistoric times; these earlier habitats consisted of larger bodies of surface water distributed throughout the peninsula, surrounded by vegetation that belongs to wetlands interspersed with common elements of the xeric scrub.
The Isla Santa Catalina Leaf-toed Gecko (Phyllodactylus bugastrolepis) is an endemic reptile to the Gulf of California xeric scrub, occurring only on Isla Santa Catalina, and often found in dead cacti. Other reptile species found here include: the endemic Santa Catalina Island Whiptail (Cnemidophorus catalinensis), seen only on Santa Catalina Island in the Gulf of California; the endemic Santa Catalina Island Spiny Lizard (Sceloporus lineatulus); the endemic San Lorenzo Islands Lizard (Uta antiqua); the endemic Salsipuedes Island Whiptail (Cnemidophorus canus), restricted in occurrence to endemic to the islands of Salsipuedes, San Lorenzo Norte and San Lorenzo Sur ; the endemic Raza Island Leaf-toed Gecko (Phyllodactylus tinklei), found on Raza Island; the endemic Santa Cruz Leaf-toed Gecko (Phyllodactylus santacruzensis); the endemic Isla Partida Del Norte Leaf-toed Gecko (Phyllodactylus partidus), found solely on Isla Partida Norte and Cardonosa Este, in the Gulf of California; the endemic Angel Island Leaf-toed Gecko (Phyllodactylus angelensis), found only on several Gulf of California islands in the county of Islas Angel de la Guarda; the endemic Las Animas Island Gecko (Phyllodactylus apricus); and the near-endemic Marbled Whiptail (Cnemidophorus marmoratus), the latter of which occupies burrows in sandy soils.
There are a number of mammalian taxa present in the Gulf of California xeric scrub, including: Angel Island Mouse (Peromyscus guardia CR), an ecoregion endemic known only from Ángel de la Guarda Island in the northern Gulf of California, México; the ecoregion endemic Burt's Deermouse (Peromyscus caniceps CR), known only from Montserrat Island, Baja California Sur, Mexico; Baja California Rock Squirrel (Spermophilus atricapillus EN), a Baja California endemic; and the Fish-eating Bat (Myotis vivesi VU), which is found along in the coastal zone of Baja California and Sonora. Bunker's Woodrat (Neotoma bunkeri EX) was previously endemic to the ecoregion and is now extinct.
- C. Michael Hogan & World Wildlife Fund. 2013."Gulf of California xeric scrub". Encyclopedia of Earth, National Council for Science and the Environment, Washington DC ed.Mark McGinley.
- S. Alvarez, P. Galina, y L. Grismer. 1997. Anfibios y reptiles. Pages 125-142 in L. Arriaga, y R. Rodríguez-Estrella (editors). Los Oasis de la Península de Baja California. México: CIBNOR. ISBN: 8449414180
Molecular Biology and Genetics
Barcode data: Olneya tesota
Statistics of barcoding coverage: Olneya tesota
Public Records: 2
Specimens with Barcodes: 2
Species With Barcodes: 1
National NatureServe Conservation Status
Rounded National Status Rank: N4 - Apparently Secure
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.
The Desert Ironwood grows as a bush or tree and reaches heights of about 10 metres (33 ft), and average trunk diameters of about 60 cm (24 in); 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 °C (36 °F). In continual drought conditions leaves will be lost.
Leaves are bluish-green and pinnate compound. Leaves are arranged on a petiole, 6 in (15 cm) long, with 6-9 leaflets-(or variously up to 15, 7, 7-opposite, and one terminal), each being 0.7 to 2.5 cm (0.28 to 0.98 in). At the base of each pinnate leaf petiole grow two thorns, about 1 cm (0.39 in) 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, and light reddish brown. When seedpods are ripened two other species Parkinsonia florida-(Blue Palo Verde), and Acacia constricta-(Catclaw Acacia) have similar light red brownish colors. Catclaw acacia seedpods are noticeably J-shaped and of shorter length.
Range and location
The Desert Ironwood, Olneya is native to the southwestern United States and the extreme northwest of Northern Mexico in the north, western-(Baja California Peninsula) and southeastern 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 southeast Southern California, is in western and southern Arizona, and Sonora state Mexico. Its range in Sonora state Mexico 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 south-central Arizona is named for Olneya tesota.
An indicator species
Olneya tesota is an indicator species of the Sonoran Desert region, The Sonoran Desert has one other species with the identical north-south, and east-west range. The seasonally migrating Lesser Long-nosed Bat follows the bloom season of various species from south to north and extends into the same regions of the Sonoran Desert as Olneya; (their ranging maps are virtually identical). The bat ranges from southern Baja California del Sur and north into the southwestern United States.
In the north, both species define the Colorado Desert subregion of the Sonoran Desert surrounding the northern end of the Gulf of California; further south in the Baja Peninsula the sub-division is defined as the Vizcaino Desert.
Other winter time and permanent ranges of the bat extend into northern countries of Central America.
Use and workability
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.
Due to its considerable hardness, processing desert ironwood is difficult. Final treatment of the wood with solutions can also be difficult because of its high density.
|Wikimedia Commons has media related to Olneya tesota.|
- Little. Atlas of United States Trees, Volume 3, Minor Western Hardwoods, Little, Elbert L, 1976, US Government Printing Office. Library of Congress No. 79-653298. Map 103, Olneya tesota.