By Lucía Rodríguez Sánchez, Director of Research, Finca Leola S.A.
Common name: almendro, mountain almendro, tonka bean tree
Commercial name: tonka bean wood
The wood of the almendro has an extraordinary hardness, and it is considered as one of the heaviest woods around the world. But it was not used until the mid-1980s because it was so difficult to saw and work with due to its weight and density. After that, with the new chain saw technology using higher carbon steel or the diamond-tipped type of chain saw, these big trees have been disappearing from the landscape. This handsome wood is becoming more and more popular, as its hardness makes it useful in heavy construction projects like railroad and bridge building. It rates high in mechanical resistance, making it very valuable in industries like the manufacture of sporting goods. The transition between brown-yellow sapwood and yellow-red heartwood is very gradual and difficult to detect, making this wood even more attractive.
Dipteryx panamensis is an endemic tree species, meaning that it has a narrow distribution. It is only located in the southern Nicaragua area, Costa Rica, Panama, and Colombia, where it grows primarily in the lowlands of the Atlantic plains.
It is an emergent tree, in humid and very humid tropical forests, where annual temperatures vary between 24º and 30ºC (75º and 86ºF), and the annual rainfall is more than 3500 mm (138 inches), at elevations ranging from 20 to 1000 meters (66 to 3281 feet) above sea level. This tree is quite abundant in the north region of Costa Rica, where until 1999 it averaged two trees per hectare with diameters larger than 50 cm (19.5 inches).
Despite being a slow-growing tree, in the natural forest Dipteryx has done best in clearings and well-illuminated forest edges. It also does well in grasslands and ranchlands. This tree may reach a great height, a condition that allows the great green macaw (Ara ambigua) to nest safely in the holes left by dry branches.
According to the COSEFORMA Project (1999), in many of the north region’s plantations, this species has been growing very well, with an average growth of 1.7 cm (0.7 inch) in diameter and 1.8 m (6 feet) in height per year during the first 6 years, which makes it a promising species for reforestation in Costa Rica’s North Zone.
Dipteryx panamensis is a large-size tree that can reach 60 m (197 feet) in height and 1 to 1.6 m (3.25 to 5.25 feet) in diameter. Some reach 2 m (6.5 feet) in diameter. It has a cylindrical trunk with ample basal roots but without buttresses (over very humid soils, basal roots could grow higher, seeming like buttresses although they are not). It has a grey-red-brown, smooth bark with vertical lenticels (spongy, raised cells that permit gas exchange between the interior of the tree and the atmosphere), ascendant (up-reaching) branches, and a semispherical crown. The blooming period is mainly between May and September. The purple-pink flowers grouped at the sides or ends of the branches make the forest look gorgeous when the almendro trees are in bloom.