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

evergreen In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, which ...

or semi-evergreen

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

, native to eastern and southern Mexico, Guatemala and Honduras.Kew World Checklist of Selected Plant Families
/ref> Although previously reported from the Andes, further collections showed these to be the similar species ''

Alnus acuminata ''Alnus acuminata'' is a species of deciduous tree in the Betulaceae family. It is found in montane forests from central Mexico to Argentina.Zuloaga, F. O., O. N. Morrone, M. J. Belgrano, C. Marticorena & E. Marchesi. (eds.) 2008. Catálogo de la ...

'', 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, including only woody plants with secondary growth, plants that are ...

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 A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...

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''). They contain many, usually unisexual flowers, arranged cl ...

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 f ...

and Sierra Madre del Sur, 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 ''Alnus jorullensis'' may be ''

'', 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, 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 ...

References

{{Taxonbar, from=Q3291973 jorullensis Trees of Mexico 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