Balanites maughamii subsp. maughamii
Green-thorn, Torchwood, Groendoring
A high-branching tree with fluted trunk
Trees are typically medium-sized to tall, high branching and with a rounded crown. Some trees may reach 20 metres in height.
Note the fluted trunk at the base of the tree, which is an early clue to its identity.
Young branches zig-zag distinctly.
The combination of forked spines and paired leaflets is unique among Kruger's trees. Carissa bispinosa has forked spines, but its leaves are simple, and the plant exudes white, milky latex when cut or damaged.
At first glance, these may look like simple leaves.
Balanites maughamii has compound, bipinnate leaves with two leaflets. Two leaves, each with two leaflets, grow from each node, as shown in the image above.
Leaflets are ovate to almost round in shape. The base is asymmetric and the midrib is slightly off-centre at the base. Margins are entire. Petiolules are short.
Young leaves are covered in velvety hairs, not persisting on the upper surface to maturity.
Leaf length varies up to 8 cm.
The Balanites genus has an unusual flowering pattern. Typically, a tree will only flower every second year, and flowering in that season can be intermittent. Flowering is from early summer until about November.
Flowers are small yellowish-green and inconspicuous, each about 1 to 2 cm in diameter. They are bisexual.
The flowers have 5 petals and are actinomorphic. This means they can be divided into mirror-image halves by a straight line passing in any direction through the mid-point.
The outer surfaces of petals are often densely hairy.
Up to 7 flowers grow together in each cyme in leaf axils.
The fruit in this image is cigar-shaped, but fruits may vary from oval to elongated. Five shallow grooves run down the length of the fruit.
The green colour of the fruit-bearing stem green, shown above, is characteristic of the new season's growth.
Fruiting occurs from mid summer to March, with ripening in autumn to early winter. Ripe fruit is yellowish.
The seeds yield an colourless and tasteless flammable oil, and the seeds in dry kernels produce a bright flame when set alight.
An interesting feature of this species is that green fruit, when placed in the water, exudes a poison that kills some fish, tadpoles and other aquatic life. Farmers may use the green fruits to reduce aquatic life in dams and reservoirs.
Ripe fruit is edible, but not tasty and not in demand by humans.
Another curious feature is that Torchwoods have branches of two kinds. One is spiny, and it does not bear flowers or fruits. The other is flower- and fruit-bearing, but mostly unarmed, or with small spines.
Balanites maughamii trees are locally common in certain types of soils, but, being fairly selective about soils types, the species is not widespread. These trees favour sandy soils among sandstone outcrops, alluvial ground near rivers and pans and granitic soils in open woodland.
Trees can be spotted from Berg-en-Dal to Crocodile Bridge in the south, and they are common around Skukuza. That distribution extends up to the Orpen area and on to Olifants.
The species also occurs in the wider Punda Maria to Pafuri regions and in the N’wambiya sandveld.
The wood is good quality and hard, and is used to make smaller implements, but very little commercial use is made of the timber.
The name Balanites was coined from the Greek word for an acorn, and it refers to fruit of the Balanites genus.
The common name Torchwood probably relates to the fact that the wood is dense and hard, and burns with a bright, long-lasting flame. With high oil content, dried fruits burn easily a brightly.
Dried fruits are reportedly useful for lighting campfires!
