Hartweg's Pine
Encyclopedia
Hartweg's Pine, Pinus hartwegii; syn. P. rudis, P. donnell-smithii) is a pine
native to the mountain
s of Mexico
and Central America
east to Honduras
. It is a very high altitude species, growing at altitudes of 2500-4300 m, and forms the alpine tree line on most of Mexico's higher mountains. It is named after Karl Theodor Hartweg
, who discovered it in 1838. It grows on both mountain ranges Sierra Madre Occidental
and Sierra Madre Oriental
(29° North latitude) from Chihuahua State and Nuevo León
(26°) to the highest peaks on the Mountains of El Salvador
- Honduras
border (15° North latitude). On Sierra Madre Occidental
there is a type of this pine that 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 altitudes. Even at the alpine tree line, this tree is not damaged by the cold and wind-blown ice present at that altitude. Consequently, Pinus hartwegii has been studied as an evolutionary unique member on tree line ecophysiology
.
Pinus hartwegii is an evergreen
tree
reaching 20-30 m in height, with a broad, rounded crown. The bark
is thick, dark grey-brown, and scaly or fissured. The leaves
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 seed
s 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 Montezuma Pine (P. montezumae), differing from it in the shorter leaves, black (not brown) and smaller cones; it replaces Montezuma Pine at high altitudes, and often hybridises with it where they meet at middle altitudes.
Pine
Pines are trees in the genus Pinus ,in the family Pinaceae. They make up the monotypic subfamily Pinoideae. There are about 115 species of pine, although different authorities accept between 105 and 125 species.-Etymology:...
native to the mountain
Mountain
Image:Himalaya_annotated.jpg|thumb|right|The Himalayan mountain range with Mount Everestrect 58 14 160 49 Chomo Lonzorect 200 28 335 52 Makalurect 378 24 566 45 Mount Everestrect 188 581 920 656 Tibetan Plateaurect 250 406 340 427 Rong River...
s of Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
and Central America
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
east to Honduras
Honduras
Honduras is a republic in Central America. It was previously known as Spanish Honduras to differentiate it from British Honduras, which became the modern-day state of Belize...
. It is a very high altitude species, growing at altitudes of 2500-4300 m, and forms the alpine tree line on most of Mexico's higher mountains. It is named after Karl Theodor Hartweg
Karl Theodor Hartweg
Karl Theodor Hartweg was a German botanist. He collected numerous new species of plants in Colombia, Ecuador, Guatemala, Mexico and California in the United States, collecting for the London Horticultural Society...
, who discovered it in 1838. It grows on both mountain ranges Sierra Madre Occidental
Sierra Madre Occidental
The Sierra Madre Occidental is a mountain range in western Mexico.-Setting:The range runs north to south, from just south of the Sonora–Arizona border southeast through eastern Sonora, western Chihuahua, Sinaloa, Durango, Zacatecas, Nayarit, Jalisco, Aguascalientes to Guanajuato, where it joins...
and Sierra Madre Oriental
Sierra Madre Oriental
The Sierra Madre Oriental is a mountain range in northeastern Mexico.-Setting:Spanning the Sierra Madre Oriental runs from Coahuila south through Nuevo León, southwest Tamaulipas, San Luis Potosí, Querétaro, and Hidalgo to northern Puebla, where it joins with the east-west running Eje Volcánico...
(29° North latitude) from Chihuahua State and Nuevo León
Nuevo León
Nuevo León It is located in Northeastern Mexico. It is bordered by the states of Tamaulipas to the north and east, San Luis Potosí to the south, and Coahuila to the west. To the north, Nuevo León has a 15 kilometer stretch of the U.S.-Mexico border adjacent to the U.S...
(26°) to the highest peaks on the Mountains of El Salvador
El Salvador
El Salvador or simply Salvador is the smallest and the most densely populated country in Central America. The country's capital city and largest city is San Salvador; Santa Ana and San Miguel are also important cultural and commercial centers in the country and in all of Central America...
- Honduras
Honduras
Honduras is a republic in Central America. It was previously known as Spanish Honduras to differentiate it from British Honduras, which became the modern-day state of Belize...
border (15° North latitude). On Sierra Madre Occidental
Sierra Madre Occidental
The Sierra Madre Occidental is a mountain range in western Mexico.-Setting:The range runs north to south, from just south of the Sonora–Arizona border southeast through eastern Sonora, western Chihuahua, Sinaloa, Durango, Zacatecas, Nayarit, Jalisco, Aguascalientes to Guanajuato, where it joins...
there is a type of this pine that 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 altitudes. Even at the alpine tree line, this tree is not damaged by the cold and wind-blown ice present at that altitude. Consequently, Pinus hartwegii has been studied as an evolutionary unique member on tree line ecophysiology
Ecophysiology
Ecophysiology or environmental physiology is a biological discipline which studies the adaptation of organism's physiology to environmental conditions...
.
Pinus hartwegii is an evergreen
Evergreen
In botany, an evergreen plant is a plant that has leaves in all seasons. This contrasts with deciduous plants, which completely lose their foliage during the winter or dry season.There are many different kinds of evergreen plants, both trees and shrubs...
tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
reaching 20-30 m in height, with a broad, rounded crown. The bark
Bark
Bark is the outermost layers of stems and roots of woody plants. Plants with bark include trees, woody vines and shrubs. Bark refers to all the tissues outside of the vascular cambium and is a nontechnical term. It overlays the wood and consists of the inner bark and the outer bark. The inner...
is thick, dark grey-brown, and scaly or fissured. The leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
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
Conifer cone
A cone is an organ on plants in the division Pinophyta that contains the reproductive structures. The familiar woody cone is the female cone, which produces seeds. The male cones, which produce pollen, are usually herbaceous and much less conspicuous even at full maturity...
are ovoid, 6-13 cm long, black or very dark purple, opening when mature in spring to 5-7 cm broad. The seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
s 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 Montezuma Pine (P. montezumae), differing from it in the shorter leaves, black (not brown) and smaller cones; it replaces Montezuma Pine at high altitudes, and often hybridises with it where they meet at middle altitudes.