''Alnus jorullensis'', commonly known as Mexican alder, is an

evergreen In botany, an evergreen is a plant which has Leaf, foliage that remains green and functional throughout the year. This contrasts with deciduous plants, which lose their foliage completely during the winter or dry season. Consisting of many diffe ...

or semi-evergreen

alder Alders are trees of the genus ''Alnus'' in the birch family Betulaceae. The genus includes about 35 species of monoecious trees and shrubs, a few reaching a large size, distributed throughout the north temperate zone with a few species ex ...

, native to eastern and southern

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

Guatemala Guatemala, officially the Republic of Guatemala, is a country in Central America. It is bordered to the north and west by Mexico, to the northeast by Belize, to the east by Honduras, and to the southeast by El Salvador. It is hydrologically b ...

, and

Honduras Honduras, officially the Republic of Honduras, is a country in Central America. It is bordered to the west by Guatemala, to the southwest by El Salvador, to the southeast by Nicaragua, to the south by the Pacific Ocean at the Gulf of Fonseca, ...

.Kew World Checklist of Selected Plant Families
/ref> Although previously reported from the Andes, further collections showed these to be the similar species '' A. acuminata'', commonly found in South America.

Description

''Alnus jorullensis'' is a medium-sized

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, e.g., including only woody plants with secondary growth, only ...

growing to 20–25 m tall. The leaves are obovate to elliptic, 5–12 cm long, somewhat leathery in texture with a serrated margin and glandular on the underside. The

flower Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

s are wind-pollinated

catkin A catkin or ament is a slim, cylindrical flower cluster (a spike), with inconspicuous or no petals, usually wind- pollinated ( anemophilous) but sometimes insect-pollinated (as in '' Salix''). It contains many, usually unisexual flowers, arra ...

s, produced in early spring.Nelson Sutherland, C.H. (2008). Catálogo de las plantes vasculares de Honduras. Espermatofitas: 1-1576. SERNA/Guaymuras, Tegucigalpa, Honduras

Range and habitat

''Alnus jorullensis'' grows in high-elevation forests in Mexico's

Sierra Madre Occidental The Sierra Madre Occidental is a major mountain range system of the North American Cordillera, that runs northwest–southeast through northwestern and western Mexico, and along the Gulf of California. The Sierra Madre is part of the American C ...

Sierra Madre Oriental The Sierra Madre Oriental () is a mountain range in northeastern Mexico. The Sierra Madre Oriental is part of the American Cordillera, a chain of mountain ranges (cordillera) that consists of an almost continuous sequence of mountain ranges that ...

and

Sierra Madre del Sur The Sierra Madre del Sur is a mountain range in southern Mexico, extending from southern Michoacán east through Guerrero, to the Isthmus of Tehuantepec in eastern Oaxaca. Geography The Sierra Madre del Sur joins with the Eje Volcánico Transv ...

, and in the highlands of Honduras, from 2,800 to 3,800 meters elevation. It is the most common alder in Mexico's mountains, and grows at the highest elevations. Guatemalan populations identified as ''A. jorullensis'' may be ''A. acuminata'', and its presence in Guatemala is uncertain. It occurs most commonly on moist soils, including stream and river banks, wetlands, and moist slopes, where it establishes dense stands. It is also found in open oak–pine and fir woodlands. It is an early successional species in areas disturbed by natural processes like landslides or fires, or by human activities like logging or forest clearance for pasture. In southern Mexico it is found in high-elevation tropical montane forests with cool temperatures with abundant rainfall.

Subspecies

Two subspecies are recognized: * ''Alnus jorullensis'' subsp. ''jorullensis'' – Mexico, Guatemala, Honduras * ''Alnus jorullensis'' subsp. ''lutea'' Furlow – Mexico

Cultivation

It is used for ornamental planting in warm temperate areas such as southern

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

References

{{Authority control jorullensis Trees of Northern America Trees of Central America Flora of the Sierra Madre Occidental Flora of the Sierra Madre Oriental Flora of the Sierra Madre del Sur Flora of the Trans-Mexican Volcanic Belt Plants described in 1817