''Quercus graciliformis'' (also known as the Chisos oak or slender oak) is a rare North American species of oak tree.

Description

''Quercus graciliformis'' is a

deciduous In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, a ...

tree up to tall. The leaves are elliptical or lance-shaped with 8–10 shallow lobes. The

acorn The acorn, or oaknut, is the nut of the oaks and their close relatives (genera '' Quercus'' and ''Lithocarpus'', in the family Fagaceae). It usually contains one seed (occasionally two seeds), enclosed in a tough, leathery shell, and bo ...

s are produced biennially.

Distribution

The species has been found only in the

Chisos Mountains The Chisos Mountains, also known as the Chisos, are a mountain range located in the Big Bend area of the Trans-Pecos region of Texas, United States. The mountain system covers 40 square miles (104 square km) and is contained entirely within the ...

, within

Big Bend National Park Big Bend National Park is an American national park located in West Texas, bordering Mexico. The park has national significance as the largest protected area of Chihuahuan Desert topography and ecology in the United States, and was named after ...

West Texas West Texas is a loosely defined region in the U.S. state of Texas, generally encompassing the arid and semiarid lands west of a line drawn between the cities of Wichita Falls, Abilene, and Del Rio. No consensus exists on the boundary betwe ...

, and a few miles southeast into the state of

Coahuila Coahuila (), formally Coahuila de Zaragoza (), officially the Free and Sovereign State of Coahuila de Zaragoza ( es, Estado Libre y Soberano de Coahuila de Zaragoza), is one of the 32 states of Mexico. Coahuila borders the Mexican states of N ...

in northeast Mexico. It is threatened by

habitat loss Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

. It grows on dry, rocky canyon floors at elevations above .

References

graciliformis Endemic flora of Texas Flora of Coahuila Flora of the Rio Grande valleys Big Bend National Park Plants described in 1934 Critically endangered flora of North America Critically endangered biota of Mexico Critically endangered flora of the United States Taxonomy articles created by Polbot {{Quercus-stub