''Trigonobalanus excelsa'' is a species of

plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclu ...

in the family Fagaceae. It is a tree

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

to Colombia. It is commonly known as black oak. The genus '' Trigonobalanus'' is related to the true

oak An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably ''L ...

s (''Quercus'') and includes three known species, ''T. excelsa'' and two species native to Southeast Asia.

Description

''Trigonobalanus excelsa'' is a tree which can grow to 20-40 meters tall.

Range and habitat

''Trigonobalanus excelsa'' is known from five locations in the Colombian Andes. These locations are on different mountain ranges and distant from one another. The species' estimated area of occupancy (AOO) is less than 500 km². * The largest population is in

Huila Department Huila () is one of the departments of Colombia. It is located in the southwest of the country, and its capital is Neiva, Colombia, Neiva. Demography and Ethnography Huila is a department that has a population of 1,122,622 inhabitants, of whic ...

at the southern end of the Cordillera Oriental. It includes a black oak forest in Cueva de los Guácharos National Natural Park totaling 40,000 ha, and mountaintop black oak groves 50 km north in the towns of Pitalito, Suaza, Timaná, and Acevedo. Black oak is found only on the western slope of the cordillera. * In Guantentá-Río Fonce Flora and Fauna Sanctuary near Santander in the Cordillera Oriental, in small patches in riparian corridors, among forests of white oak (''

Quercus humboldtii ''Quercus humboldtii'', commonly known as the Andean oak, Colombian oak or roble, is a species of oak found only in Colombia and Panamá. It is named for Alexander von Humboldt. Description ''Quercus humboldtii'' is an evergreen tree which gro ...

''). * In the municipalities of Amalfi, Antioquia and Serranía de San Lucas, Bolivar in the Cordillera Central, 600 and 700 km north of the main Huila Department population. * In Farallones de Cali National Natural Park and in Valle del Cauca in the Cordillera Occidental, about 200 km from the main Huila population. It grows in humid Andean montane forests between 1,400- and 2,200-meters elevation. It is found in mixed forests and in monospecific stands, typically in areas with steep slopes and poor soils. Some populations grow near forests of white oak (''Quercus humboldtii'').

Conservation

The species' conservation status is assessed as

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and in ...

. It is known from relatively small and isolated populations. Some populations are in protected areas. The main population in Huila is not protected and is threatened with habitat loss from ongoing deforestation. Other populations, like those in Antioquia and Bolivar departments, have been greatly reduced by deforestation, and survive only in remnant forest patches.

References

{{Authority control Fagaceae Endemic flora of Colombia Trees of South America Vulnerable plants Taxonomy articles created by Polbot Flora of the northwestern Andean montane forests