Acacia burkei, commonly known as the Black Monkey Thorn, is a distinctive and robust tree species. This deciduous tree is recognized for its imposing size and characteristic thorny branches. It is a significant component of its native ecosystems, contributing both ecologically and through various human uses.
Identification and Characteristics
The Black Monkey Thorn is a large, spreading deciduous tree, typically growing between 12 to 25 meters tall, forming a flat or open crown. It usually develops a single stem, with branches often appearing higher up its trunk. The bark on younger branches is velvety reddish-brown, transitioning to an irregularly fissured, greyish to brownish-black, and flaking texture on older trunks.
Its leaves are bipinnate, displaying dark green leaflets. Each leaf consists of 3 to 10 pairs of pinnae, with each pinna bearing 4 to 10 pairs of smaller leaflets that are velvety, particularly on their veins. Individual leaves can measure 25 to 70 millimeters long, while the leaflets are 12 to 25 millimeters in length. The tree produces yellowish-white or creamy, scented flowers arranged in small spikes, which emerge at the ends of its branches. These spikes, ranging from 15 to 85 millimeters long, appear during late spring to early summer, from October to January.
Following the flowering period, bright red, flat, bean-like seed pods develop, maturing from December to May. These pods have a pointed tip, turn red-brown to dark brown as they ripen, and eventually black, displaying prominent veins before splitting open on the tree. Its sharp, blackish-brown, and strongly hooked thorns are a defining feature. These recurved thorns grow in pairs, positioned just below the leaf nodes, and measure between 3 and 9 millimeters long.
Natural Habitat and Ecological Role
Acacia burkei is indigenous to Southern Africa, with its natural distribution spanning southeastern Botswana, southeastern Zimbabwe, Mozambique, Eswatini, and various provinces of South Africa. This species thrives in hot and dry deciduous woodlands, and is commonly found across bushveld, grassland, savanna, and thornveld regions. It adapts to a range of soil conditions, often occurring on sandy soils and rocky slopes within its native environment.
The Black Monkey Thorn plays a significant role within its ecosystem, providing resources for wildlife. Its leaves and pods serve as a food source for a variety of animals, including giraffe, monkeys, elephants, antelope, kudu, nyala, and impala. The tree’s fissured bark offers foraging opportunities and attracts insect-eating birds such as woodpeckers and red-billed wood hoopoes. It also acts as a larval host plant for specific butterfly species.
Cultivation and Care
When considering Acacia burkei for cultivation, site selection is important due to its mature size and root system. This tree is best suited for large gardens or parks, as its aggressive roots require planting at least 5 meters away from buildings or paved areas. It prefers locations that receive full sun, though it can tolerate semi-shade conditions.
The Black Monkey Thorn adapts well to various soil types but thrives in well-drained, sandy soils. Once established, it is drought hardy and has low watering requirements, making it a water-wise choice. As a deciduous species, Acacia burkei is frost hardy.
Pruning can be undertaken to maintain the tree’s shape or for safety. While specific pest and disease issues are not widely reported, the tree’s bark attracts birds that feed on insects. Propagation of Acacia burkei is typically achieved from seed. It is generally considered to have a relatively fast growth rate.
Uses and Significance
Acacia burkei is valued for its robust wood, which features a dark brown heartwood and yellowish sapwood. This wood is known for its strength, weight, and resistance to termites, making it a material for fence posts, furniture, and tool handles. It also serves as good firewood, producing long-lasting coals. Its timber is utilized in traditional carpentry and craftsmanship, contributing to the creation of various artisanal goods.
Beyond its timber, the tree holds considerable ornamental appeal, providing dense shade and serving as an attractive specimen in large garden settings. Its distinctively fissured bark adds to its aesthetic value. The species is also a favored choice for bonsai cultivation, owing to its fine leaves and capacity for training.
In traditional practices, the edible gum exuded by the tree has been consumed by people, monkeys, and bush babies. The bark and roots have been used in traditional medicine to address eye and back complaints, and the roots are also a source of yellow dye. Its dense canopy provides shade, making it a beneficial addition to gardens and landscapes.