''Pinus hartwegii'' (

syn. The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linnae ...

''P. rudis'', ''P. donnell-smithii''), Hartweg's pine or pino de las alturas, is a pine native to the mountains of Mexico and Central America east to

Honduras Honduras, officially the Republic of Honduras, is a country in Central America. The republic of Honduras is bordered to the west by Guatemala, to the southwest by El Salvador, to the southeast by Nicaragua, to the south by the Pacific Oce ...

. It is named after Karl Theodor Hartweg, who described it in 1838.

Distribution

''Pinus hartwegii'' is a very high elevation species, growing at elevations of . It forms the alpine tree line on most of Mexico's higher mountains. It grows on both the Sierra Madre Occidental and

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 ...

(mountain ranges) (29° North latitude) from

Chihuahua Chihuahua may refer to: Places *Chihuahua (state), a Mexican state **Chihuahua (dog), a breed of dog named after the state **Chihuahua cheese, a type of cheese originating in the state **Chihuahua City, the capital city of the state **Chihuahua Mun ...

State and

Nuevo León Nuevo León () is a state in the northeast region of Mexico. The state was named after the New Kingdom of León, an administrative territory from the Viceroyalty of New Spain, itself was named after the historic Spanish Kingdom of León. With a ...

(26°) to the highest peaks in the mountain ranges on the

El Salvador El Salvador (; , meaning " The Saviour"), officially the Republic of El Salvador ( es, República de El Salvador), is a country in Central America. It is bordered on the northeast by Honduras, on the northwest by Guatemala, and on the south b ...

—

border (15° North latitude). In the Sierra Madre Occidental this pine grows with very dry winters and a very heavy rainy season in summer, with constant frosts from October to March. This pine does not acquire the dwarfed and contorted shape shared by many species at high elevation. Even at the alpine tree line, this tree is not damaged by the cold and wind-blown ice present at that elevation. Consequently, ''Pinus hartwegii'' has been studied as an evolutionarily unique member on tree line ecophysiology. Pinus hartwegii Cofre de Perote

Description

''Pinus hartwegii'' is an evergreen tree reaching in height, with a broad, rounded crown. The

bark Bark may refer to: * Bark (botany), an outer layer of a woody plant such as a tree or stick * Bark (sound), a vocalization of some animals (which is commonly the dog) Places * Bark, Germany * Bark, Warmian-Masurian Voivodeship, Poland Arts, ...

is thick, dark grey-brown, and scaly or fissured. The

leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

are needle-like, dark green, five (occasionally four) per fascicle, 10–20 cm long and 1.2-1.5 mm thick, the persistent fascicle sheath 1.5–2 cm long. The cones are ovoid, 6–13 cm long, black or very dark purple, opening when mature in spring to 5–7 cm broad. The seeds are winged, 5–6 mm long with a 1.5-2.5 cm wing. Pollination is in late spring, with the cones maturing 20–22 months after. It is closely related to ''Pinus montezumae'' (Montezuma pine) , differing from it in the shorter leaves, black (not brown) and smaller cones; it replaces Montezuma pine at high elevations, and often hybridises with it where they meet at middle elevations.

References

External links

{{Taxonbar, from=Q136695 hartwegii Trees of Northeastern Mexico Trees of Chiapas Trees of Guerrero Trees of Michoacán Trees of Puebla Trees of Oaxaca Trees of Veracruz Trees of Guatemala Trees of El Salvador Trees of Honduras Trees of Central Mexico Flora of Northeastern Mexico Flora of the Sierra Madre Occidental Flora of the Sierra Madre Oriental Flora of the Trans-Mexican Volcanic Belt Least concern flora of North America