''Pinus merkusii'', the Merkus pine or Sumatran pine, is a

pine A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. ''World Flora Online'' accepts 134 species-rank taxa (119 species and 15 nothospecies) of pines as cu ...

native to the

Malesia Malesia is a biogeographical region straddling the Equator and the boundaries of the Indomalayan and Australasian realms. It is a phytogeographical floristic region in the Paleotropical kingdom. It was first recognized as a distinct region ...

region of southeast

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

, and the only one that occurs naturally south of the equator.

Description

''Pinus merkusii'' is a medium-sized to large

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 ...

, reaching tall and with a trunk diameter of up to . The bark is orange-red, thick and deeply fissured at the base of the trunk, and thin and flaky in the upper crown. The

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

('needles') are in pairs, very slender, long and less than thick, green to yellowish green. The cones are narrow conic, long and broad at the base when closed, green at first, ripening glossy red-brown. They open to 4–5 cm broad at maturity to release the seeds. The seeds are long, with a wing, and are wind-dispersed.

Related species

''Pinus merkusii'' is closely related to the Tenasserim pine (''P. latteri''), which occurs farther north in southeast Asia from

Myanmar Myanmar, officially the Republic of the Union of Myanmar; and also referred to as Burma (the official English name until 1989), is a country in northwest Southeast Asia. It is the largest country by area in Mainland Southeast Asia and has ...

Vietnam Vietnam, officially the Socialist Republic of Vietnam (SRV), is a country at the eastern edge of mainland Southeast Asia, with an area of about and a population of over 100 million, making it the world's List of countries and depende ...

; some botanists treat the two as conspecific (under the name ''P. merkusii'', which was described first), but ''P. latteri'' differs in longer () and stouter (over 1 mm thick) leaves and larger cones with thicker scales, the cones often remaining closed for some time after maturity. It is also related to the group of

Mediterranean The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern ...

pines including

Aleppo pine ''Pinus halepensis'', commonly known as the Aleppo pine, also known as the Jerusalem pine, is a pine native to the Mediterranean region. It was officially named by the botanist Philip Miller in his 1768 book ''The Gardener's Dictionary''; he pro ...

and

Turkish pine ''Pinus brutia'', commonly known as the Turkish pine and Calabrian pine, is a species of pine native to the eastern Mediterranean region. The bulk of its range is in Turkey, but certain varieties are naturalized as far east as Afghanistan. It is ...

, which share many features with it.

Distribution

It can be found mainly in

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian Ocean, Indian and Pacific Ocean, Pacific oceans. Comprising over List of islands of Indonesia, 17,000 islands, including Sumatra, ...

in the mountains of northern

Sumatra Sumatra () is one of the Sunda Islands of western Indonesia. It is the largest island that is fully within Indonesian territory, as well as the list of islands by area, sixth-largest island in the world at 482,286.55 km2 (182,812 mi. ...

, and with two outlying populations in central Sumatra on Mount Kerinci and Mount Talang, and in the

Philippines The Philippines, officially the Republic of the Philippines, is an Archipelagic state, archipelagic country in Southeast Asia. Located in the western Pacific Ocean, it consists of List of islands of the Philippines, 7,641 islands, with a tot ...

on Mindoro and in the

Zambales Mountains The Zambales Mountains is a mountain range in western Luzon. The mountains spread along a north-south axis, separating Luzon's central plain from the South China Sea. The range extends into five Provinces of the Philippines, provinces: Zambales, ...

on western

Luzon Luzon ( , ) is the largest and most populous List of islands in the Philippines, island in the Philippines. Located in the northern portion of the List of islands of the Philippines, Philippine archipelago, it is the economic and political ce ...

. Isolated populations of ''Pinus merkusii'' can be found in

Mainland Southeast Asia Mainland Southeast Asia (historically known as Indochina and the Indochinese Peninsula) is the continental portion of Southeast Asia. It lies east of the Indian subcontinent and south of Mainland China and is bordered by the Indian Ocean to th ...

, such as Kirirom National Park, on the Cardamom Mountains in

Cambodia Cambodia, officially the Kingdom of Cambodia, is a country in Southeast Asia on the Mainland Southeast Asia, Indochinese Peninsula. It is bordered by Thailand to the northwest, Laos to the north, and Vietnam to the east, and has a coastline ...

and Bidoup Núi Bà National Park on the Đà Lạt Plateau in

. The population in central Sumatra, between 1° 40' and 2° 06' S latitude, is the only natural occurrence of any member of the

Pinaceae The Pinaceae (), or pine family, are conifer trees or shrubs, including many of the well-known conifers of commercial importance such as Cedrus, cedars, firs, Tsuga, hemlocks, Pinyon_pine, piñons, larches, pines and spruces. The family is incl ...

south of the

Equator The equator is the circle of latitude that divides Earth into the Northern Hemisphere, Northern and Southern Hemisphere, Southern Hemispheres of Earth, hemispheres. It is an imaginary line located at 0 degrees latitude, about in circumferen ...

. It generally occurs at moderate altitudes, mostly , but occasionally as low as and up to .

References

Merkusii Trees of Sumatra Trees of the Philippines Vulnerable plants {{conifer-stub