''Fraxinus anomala'' is a species of ash tree known by the common name single-leaf ash. It is native to the southwestern United States and northern

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

, where it grows in a number of habitats including

desert scrub Deserts and xeric shrublands are a biome defined by the World Wide Fund for Nature. Deserts and xeric (ancient Greek xērós, “dry") shrublands form the largest terrestrial biome, covering 19% of Earth's land surface area. Ecoregions in this ...

and chaparral. It is unusual in the genus in that some (though not all) specimens have simple leaves instead of the

pinnate Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, and in ...

leaves more characteristic of the group.

Description

''Fraxinus anomala'' is a deciduous shrub or small tree approaching maximum heights of five to six meters. The leaf may be simple or it may be compound, composed of up to five leaflets which look like individual leaves. Each leaflet is oval-shaped to round and may have teeth along the edges. The nondescript brownish flowers lack petals. The fruit is a flat samara up to two centimeters long and one wide, green when young and tan to brown when mature. The samaras hang in bunches.

Distribution

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

, singleleaf ash is found along the Arizona transition zone of the

Mogollon Rim The Mogollon Rim ( or or ) is a topographical and geological feature cutting across the northern half of the U.S. state of Arizona. It extends approximately , starting in northern Yavapai County and running eastward, ending near the border ...

. In northern Arizona's Grand Canyon, the range extends down the main canyons from southern and southeastern

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...

, its major range area, where the Canyon Lands also show the range entering upper reaches of river basins flowing from western

Colorado Colorado (, other variants) is a state in the Mountain states, Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the wes ...

–

and

Dolores River The Dolores River is a tributary of the Colorado River, approximately long, in the U.S. states of Colorado and Utah. The river drains a rugged and arid region of the Colorado Plateau west of the San Juan Mountains. Its name derives from the Sp ...

s; also the shorter

Yellowjacket Yellowjacket or yellowjacket is the common name in North America for predatory social wasps of the genus, genera ''Vespula'' and ''Dolichovespula''. Members of these genera are known simply as "wasps" in other English-speaking countries. Most of ...

and McElmo Rivers in Colorado's extreme southwest. In the

Mojave Desert The Mojave Desert ( ; mov, Hayikwiir Mat'aar; es, Desierto de Mojave) is a desert in the rain shadow of the Sierra Nevada mountains in the Southwestern United States. It is named for the indigenous Mojave people. It is located primarily ...

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

it is found in the

sky island Sky islands are isolated mountains surrounded by radically different lowland environments. The term originally referred to those found on the Mexican Plateau, and has extended to similarly isolated high-elevation forests. The isolation has s ...

chaparral and woodland

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

s. Minor locales also occur in southern

Nevada Nevada ( ; ) is a state in the Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the 7th-most extensive, ...

and southern

Wyoming Wyoming () is a state in the Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to the s ...

.Biota of North America Program, ''Fraxinus anomala''
/ref>

References

External links

Jepson Manual Treatment - ''Fraxinus anomala''''Fraxinus anomala'' - Photo gallery
{{Taxonbar, from=Q1144955 anomala Trees of Northwestern Mexico Trees of the Southwestern United States Trees of the Northwestern United States Trees of the South-Central United States Plants described in 1871 Flora without expected TNC conservation status