''Xanthostemon verdugonianus'', commonly known as mangkono or Philippine ironwood, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclud ...

in the family

Myrtaceae Myrtaceae, the myrtle family, is a family of dicotyledonous plants placed within the order Myrtales. Myrtle, pōhutukawa, bay rum tree, clove, guava, acca (feijoa), allspice, and eucalyptus are some notable members of this group. All speci ...

. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the islands of the

Visayas The Visayas ( ), or the Visayan Islands (Bisayan languages, Visayan: ''Kabisay-an'', ; tl, Kabisayaan ), are one of the three Island groups of the Philippines, principal geographical divisions of the Philippines, along with Luzon and Mindanao ...

Palawan Palawan (), officially the Province of Palawan ( cyo, Probinsya i'ang Palawan; tl, Lalawigan ng Palawan), is an archipelagic province of the Philippines that is located in the region of Mimaropa. It is the largest province in the country in ...

, and northeastern

Mindanao Mindanao ( ) ( Jawi: مينداناو) is the second-largest island in the Philippines, after Luzon, and seventh-most populous island in the world. Located in the southern region of the archipelago, the island is part of an island group of ...

. It is valued for its extremely durable and heavy timber. It is threatened by

habitat loss Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

Names

Mangkono (also spelled mangkuno or mancono) is also known as ''palo de hierro'' ("iron wood") in Spanish. It is also known as Magkuno (Magcuno) or Makano (Macano) in Surigaonon; and Magkuno or Tamaulauan in

Visayan Visayans (Visayan: ''mga Bisaya''; ) or Visayan people are a Philippine ethnolinguistic group or metaethnicity native to the Visayas, the southernmost islands of Luzon and a significant portion of Mindanao. When taken as a single ethnic group, ...

Description

Mangkono has a maximum recorded diameter of around , and a maximum recorded height of . However most trees rarely exceed in diameter and in height. The trunk is usually highly irregular with frequent branching. The bark is slate white in color and has a peeling appearance. The sapwood is usually pale reddish in color while the heartwood is deep red to brown. The leaves are around in length, and in width. They are dark green in color on the upper side and pale whitish green on the underside. They have a smooth, leathery texture. They are simple and are arranged alternately. The inflorescence is borne at the ends of branches. They are bright red in color and spring from the apex of the

peduncle Peduncle may refer to: *Peduncle (botany), a stalk supporting an inflorescence, which is the part of the shoot of seed plants where flowers are formed *Peduncle (anatomy), a stem, through which a mass of tissue is attached to a body **Peduncle (art ...

s. Each inflorescence has multiple peduncles, each with 3 to 6 flowers, for a total of 13 to 20 per inflorescence. Around 12 fruits develop from the flowers. The fruits are dehiscent and septicidal, with two or three sections that open when ripe to disperse small semicircular seeds.

Timber

''Xanthostemon verdugonianus'' is known to be the hardest Philippine hardwood species. Cutting a 70-cm thick tree with axes normally requires three hours, but cutting a Mangkono tree with the same diameter usually takes two to four days. Diamond-point saws have been used exclusively but a great volume of water is needed to counter overheating. Because of its inherent hardness and high density, Mangkono has long been recognized as a substitute for the world-famous '' Lignum vitae'' (''Guaicum officinale'' L.). Mangkono is an excellent material for the bearing or stern bushing of a steamship's propeller shaft. Its other uses are as rollers, shears, saw guide blocks, tool handles, novelties, poles and piles for wharves and bridges, and posts for houses.

Conservation

The tree is rare and is classified as Vulnerable by the

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

due to overharvesting and habitat loss.

References

Flora of the Philippines verdugonianus Vulnerable plants Taxonomy articles created by Polbot Taxa named by Celestino Fernández-Villar {{Myrtaceae-stub