The mangkono tree is hard – so hard that it is called Philippine ironwood in English. Its density is so great that it will sink when placed in water.
Its hardness is comparable to our own hop hornbeam, which is also called ironwood. Like the hop hornbeam, mangkono presents a formidable challenge to any woodcutter who tries to cut it down. Various sources also compare its wood to lignum vitae, the wood of Guaiacum officinale, which grows in the Antilles and in Colombia.
There are two different species that are called mangkono: Xanthostemon speciosus, and Xanthostemon verdugonianus. They are both endemic to the Philippines. Xanthostemon speciosus grows in the province of Palawan, and Xanthostemon verdugonianus grows in the so-called Mangkono Triangle. The Mangkono Triangle consists of the island of Dinagat off the coast of Surigao del Norte, the island of Homonhon not far from Samar, and Babatngon in northern Leyte, according to Philstar.
In addition to its occurrence in the wild, some Filipinos are planting mangkono as a landscape tree. In particular, San Beda College has adopted it as its special tree. They were planning to use it to adorn their three campuses in Mendiola, Taytay, and Alabang, according to a PhilStar article dated January, 2010.
The tree certainly lends color to a landscape when it bursts into bloom. However, a further motive induces Filipinos to plant this particular type of tree. The IUCN Red List classifies Xanthostemon verdugonianus as a vulnerable species, and Filipinos do not want this valued endemic to pass from the national scene.
Both Xanthostemon verdugonianus and Xanthostemon speciosus belong to the plant family Myrtaceae. Other members of this family are the wax myrtle, the eucalyptus, and the guava.
According to Garden Guide, Xanthostemon verdugonianus grows to a height of 30 to 40 feet. Its fluted truck may achieve a diameter of 20 to 36 inches. It has simple leaves with pinnate venation. According to PhilStar, the leaves are eight to twelve centimeters long and three to five centimeters wide. The apices of the leaves are rounded on the pictures that I have seen, and they come to a point at the spot where they are attached to the petiole.
Mangkono produces brilliant red flowers that develop into fruits that dehisce (split apart) at maturity, thereby releasing two or three seeds that are shaped like a half moon, according to PhilStar.
The hard, durable wood is a useful material for the construction of such objects as tool handles, piles for wharfs and bridges, and posts for houses. However, because its numbers have dwindled, commercial exploitation has been almost eliminated.
The scientific name is intriguing. I imagine that “verdugonianus” comes from the Spanish word “verdugo,” which means a hangman or executioner. I suspect that it was once used in the construction of gibbets, but I have not been able to verify my suspicions.