''Bursera microphylla'', known by the common name elephant tree in English or 'torote' in Spanish, is a tree in genus ''

Bursera ''Bursera'' is a genus with about 100 described species of flowering shrubs and trees varying in size up to high. It is the type genus for Burseraceae. The trees are native (often for many species endemic) to the Americas, from the southern Uni ...

''. It grows into a distinctive sculptural form, with a thickened, water-storing or caudiciform trunk. It is found in the southwestern United States and northwestern Mexico.

Distribution

''Bursera microphylla'' is the most northerly member of the Burseraceae in North America and also perhaps the most xeromorphic (desert-adapted) species within the genus as it thrives in the extremely arid desert hills and mountains in northwest Sonora. This tree is native to northwestern Mexico (

Baja California Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...

Baja California Sur Baja California Sur (; 'South Lower California'), officially the Free and Sovereign State of Baja California Sur ( es, Estado Libre y Soberano de Baja California Sur), is the least populated state and the 31st admitted state of the 32 federal ent ...

Sinaloa Sinaloa (), officially the Estado Libre y Soberano de Sinaloa ( en, Free and Sovereign State of Sinaloa), is one of the 31 states which, along with Mexico City, comprise the Administrative divisions of Mexico, Federal Entities of Mexico. It is d ...

Sonora Sonora (), officially Estado Libre y Soberano de Sonora ( en, Free and Sovereign State of Sonora), is one of the 31 states which, along with Mexico City, comprise the Administrative divisions of Mexico, Federal Entities of Mexico. The state is d ...

and

Zacatecas , image_map = Zacatecas in Mexico (location map scheme).svg , map_caption = State of Zacatecas within Mexico , coordinates = , coor_pinpoint = , coordinates_footnotes = , subdivision_type ...

) and the southwestern United States (southern

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

and

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 ...

; especially in desert regions. This species can be found within

Organ Pipe Cactus National Monument Organ Pipe Cactus National Monument is a U.S. national monument and UNESCO biosphere reserve located in extreme southern Arizona that shares a border with the Mexican state of Sonora. The park is the only place in the United States where the ...

Cabeza Prieta National Wildlife Refuge Cabeza Prieta National Wildlife Refuge (CPNWR) is located in southwestern Arizona in the United States, along of the Mexico–United States border. It is bordered to the north and to the west by the Barry M. Goldwater Air Force Range, to the s ...

Ironwood Forest National Monument Ironwood Forest National Monument is located in the Sonoran Desert of Arizona. Created by Bill Clinton by Presidential Proclamation 7320 on June 9, 2000, the monument is managed by the Bureau of Land Management, an agency within the United State ...

Sonoran Desert National Monument Sonoran Desert National Monument is south of Goodyear and Buckeye and east of Gila Bend, Arizona. Created by Presidential proclamation on January 17, 2001, the monument is managed by the U.S. Bureau of Land Management as part of the Natio ...

, El Pinacate y Gran Desierto de Altar Biosphere Reserve,

Islas del Golfo de California Biosphere Reserve Islas is a surname. Notable people with the surname include: *Arturo Islas (1938–1991), professor of English and a novelist from Texas *Daniel Islas (born 1979), Argentine football goalkeeper *Luis Islas (born 1965), former football goalkeeper * ...

Cabo Pulmo National Park Cabo Pulmo National Park ( es, Parque Nacional Cabo Pulmo) is a national marine park on the east coast of Mexico's Baja California Peninsula, spanning the distance between Pulmo Point and Los Frailes Cape, approximately north of Cabo San Lucas ...

El Vizcaíno Biosphere Reserve The El Vizcaíno Biosphere Reserve, created in 1988, is located in Mulegé Municipality in northern Baja California Sur, at the center of the Baja California Peninsula between the Pacific Ocean and the Gulf of California. With an area of over ), ...

, Valle de los Cirios Natural Protected Area, and Sierra de San Pedro Mártir National Park, and

Anza-Borrego Desert State Park Anza-Borrego Desert State Park (, '' AN-zə bə-RAY-goh'') is a California State Park located within the Colorado Desert of southern California, United States. The park takes its name from 18th century Spanish explorer Juan Bautista de Anza and ...

. A few individuals can be found in the Fish Creek Badlands of Anza-Borrego Desert State Park, in a location between the

Vallecito Mountains The Vallecito Mountains are located in the Colorado Desert, in eastern San Diego County, Southern California. They are about north of the U.S. border with Mexico. Geography The mountains lie in Anza-Borrego Desert State Park, in an east–west ...

and

Ocotillo Wells Ocotillo Wells is an unincorporated community in San Diego County, California, United States. It is west of the Imperial County line on California State Route 78 at an elevation of . The name became official in 1962 when it was adopted for fe ...

. This small population represents the northernmost extent of the distribution of this species.

Description

''Bursera microphylla'' is generally a small tree with a thickened trunk and relatively small branching structure in comparison to the trunk size; it is semi-succulent and stores water in the conductive and parenchymal tissues of the trunk, lower limbs, and wood. Shreve (1964) classified the plant as a sarcocaulescent tree. The sarcocaulescent habit acts as a buffer against variation in environmental

water balance The law of water balance states that the inflows to any water system or area is equal to its outflows plus change in storage during a time interval. In hydrology, a water balance equation can be used to describe the flow of water in and out of ...

(Turner et al., 1995). The leaves are alternate, without

stipule In botany, a stipule is an outgrowth typically borne on both sides (sometimes on just one side) of the base of a leafstalk (the petiole). Stipules are considered part of the anatomy of the leaf of a typical flowering plant, although in many speci ...

s, and are mostly once-

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 ...

or twice-pinnate but can be unifoliate or trifoliate in some species (Rzedowski and Kruse 1979). ''Bursera microphylla'' reaches up to in height and its bark is light gray to white, with younger branches having a reddish color. The light foliage is made up of long, straight, flat,

legume A legume () is a plant in the family Fabaceae (or Leguminosae), or the fruit or seed of such a plant. When used as a dry grain, the seed is also called a pulse. Legumes are grown agriculturally, primarily for human consumption, for livestock f ...

-like leaves which are composed of paired leaflets. It flowers in rounded yellow buds which open into small, star-shaped, white or cream flowers. The fruit is a

drupe In botany, a drupe (or stone fruit) is an indehiscent fruit in which an outer fleshy part (exocarp, or skin, and mesocarp, or flesh) surrounds a single shell (the ''pit'', ''stone'', or '' pyrena'') of hardened endocarp with a seed (''kernel'') ...

containing a yellow stone. The leaves are characterized as deciduous, including those on species that occur in tropical subhumid and humid forests (Becerra 2005). As a response to rain and warmer temperatures, ''B. hindsiana, B. laxiflora'', and other more tropical species in Sonora begin to leaf out at any time of the year. Most species are drought deciduous, but ''B. microphylla'' keeps its leaves year-round, except under conditions of drought and cold weather. Most of the Sonoran Burseras flower in June and July, just before or just as the leaves are produced. This is probably in response to a lack of rainfall earlier in the summer before the monsoon season as this species is found in the region of Sonora lies at the western edge of an area, which regularly experiences summer monsoon storms. The fruits of species in the genus ''Bursera'' are small, drupe-like capsules, each with a single-seed. In ''B. microphylla'', the fruits develop rapidly and ripen gradually, a few at a time, and in some species many fruits remain on the trees as they begin to flower the following summer. Birds appear to be primarily responsible for seed dispersal in ''Bursera''. Gray Vireos and Ash- throated Flycatchers feed heavily on the ripe fruits of ''B. microphylla'' in the Puerto Lobos region of Sonora, Mexico during the winter months. The winter range of the Gray Vireo in Sonora closely matches the distribution of Bursera microphylla. Birds do not appear to eat the unripe fruit. Rodents sometimes gather fruits and seeds of ''Bursera''. Ants have been observed carrying away seeds of ''B. microphylla''. It has been suggested that the exfoliating papery bark of many of the trivalvate species may serve to attract the attention of birds and other animals from a distance as it rustles in the breeze (Rzedowski and Kruse 1979).

Uses

* The

Cahuilla The Cahuilla , also known as ʔívil̃uqaletem or Ivilyuqaletem, are a Native American people of the various tribes of the Cahuilla Nation, living in the inland areas of southern California.Indian Indian or Indians may refer to: Peoples South Asia * Indian people, people of Indian nationality, or people who have an Indian ancestor ** Non-resident Indian, a citizen of India who has temporarily emigrated to another country * South Asia ...

people of the

Colorado Desert California's Colorado Desert is a part of the larger Sonoran Desert. It encompasses approximately , including the heavily irrigated Coachella and Imperial valleys. It is home to many unique flora and fauna. Geography and geology The Colorado De ...

region of California reportedly used the red sap of the elephant tree for treating skin disorders and other diseases. *

Seri Seri or SERI may refer to: People *Jean Michaël Seri, an Ivorian professional footballer Places *Seri Yek-e Zarruk, Iran *Seri, Bheri, Nepal *Seri, Karnali, Nepal *Seri, Mahakali, Nepal *Seri, Raebareli, a village in Uttar Pradesh, India Oth ...

use the plant in many ways, including the wood for boxes. *It is popular as a landscape plant in southwestern US in low warm desert where it does not freeze.Soule, J.A. 2013. ''Success with Succulents''. Tierra del Sol Press

Gallery

File:BM1.jpg, ''Bursera microphylla'' on southern slope at South Mountain Municipal Park, Phoenix, Arizona. October 2008. (C. Cordova) File:BM6.jpg, ''Bursera microphylla'' growing on a granite boulder at South Mountain Municipal Park, Phoenix, Arizona. October 2008. (C. Cordova) File:BM7.jpg, ''Bursera microphylla'' growing on a granite boulder at South Mountain Municipal Park, Phoenix, Arizona. January 2010. (C. Cordova) File:BM4.jpg, ''Bursera microphylla'' growing on a granite boulder at South Mountain Municipal Park, Phoenix, Arizona. January 2010. (C. Cordova) File:BM5.jpg, ''Bursera microphylla'' growing on granite boulders at South Mountain Municipal Park, Phoenix, Arizona. January 2010. (C. Cordova) Image:Bursera-microphylla-baja.jpg, ''Bursera microphylla'' in

, Mexico File:Bursera-microphylla-organpipe.jpg, ''Bursera microphylla'' in the

Sonoran Desert The Sonoran Desert ( es, Desierto de Sonora) is a desert in North America and ecoregion that covers the northwestern Mexican states of Sonora, Baja California, and Baja California Sur, as well as part of the southwestern United States (in Arizona ...

, U.S. File:Elephanttreecerrocolorado.jpg, ''Bursera microphylla'' in the Vizcaino Desert,

, Mexico

References

External links

Jepson Manual Treatment — ''Bursera microphylla''''Bursera microphylla'' — Calphotos Photo gallery, University of California
{{Taxonbar, from=Q2367282 microphylla North American desert flora Flora of Northwestern Mexico Flora of the Southwestern United States Plants described in 1861 Cahuilla Plants used in traditional Native American medicine Caudiciform plants