Leucaena macrophylla istmensis

Cultivation Details

Leucaena macrophylla istmensis is a truly tropical form of the species, growing mainly at lower elevations to 400 metres and occasionally to 1,500 metres. It is found in areas of seasonal rainfall, with a mean annual rainfall in the range 700 - 1,500mm and a 4 - 6 month dry season^[1]. Leucaena species generally require a sunny position. They are often found in the wild on poor, shallow and dry soils, usually overlying a calcareous rock. Most of them do not thrive on acid soils. Most species experience a long dry season and are more or less drought tolerant. The plant is a common element of secondary vegetation and has the potential to spread under open ruderal conditions and become a weed^[1] A fast-growing tree^[1]. The unripe seedpods are harvested by climbing the trees and lopping the terminal branches or groups of pods, often crudely, with machetes, small knives or cutting poles. Annual pollarding in this way apparently causes only limited damage to the trees which resprout and fruit annually^[1]. This subspecies may have some potential for wood production, although this is limited by its susceptibility to damage by psyllids. In a replicated trial in Honduras, it was found to grow more than twice as fast as subsp. macrophylla and was one of the most productive taxa of all, forming a tall, single-stemmed tree with good diameter growth and high wood biomass production^[1]. The tree is moderately susceptible to damage by psyllids1518]. This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby^[2].