An attractive, small to medium-sized tree. Its leaves are bluish grey above and silvery below with strikingly straight, parallel side veins.]
This is an evergreen to semideciduous, small to medium-sized tree with a round crown. It grows to between 3 and 7 m in height. It is a single-stemmed tree with reddish-brown branchlets which are covered with lenticels and hairs when young. The bark is grey and it cracks and turns rough with age. The simple leaves are narrow and usually alternate or arranged in whorls of 3 and they are silvery bluish-grey. Older leaves appear to be dark green above and silvery below. Ozoroa paniculosa bears scented, creamy-white flowers in terminal sprays. The shiny green fruits are small, fleshy, kidney shaped drupes, usually with reddish-brown spots and turn black and wrinkled when ripe. The sexes of this tree appear on different plants.
This plant is listed as of Least Concern in the National Red Data List and this means that it is not threatened in its natural habitat.
Distribution and habitat
The common resin bush is widespread across the deciduous woodlands and bushveld areas. The populations are scattered within the bushveld and highveld regions from Zimbabwe into the northern parts of South Africa and some parts of KZN, as well as in Namibia and Botswana. They occur on rocky slopes and hillsides.
Derivation of name and historical aspects
The origin of the name Ozoroa is unknown; the species epithet paniculosa means with loose flower clusters. Ozoroa paniculosa was formerly included in the genus Heeria.
Ozoroa is a genus within the Anacardiaceae family (the mango family). This genus has around 40 species and it occurs from the South African to the Arabian Peninsula region. The plants in this genus usually have simple, alternate or whorled leaves that often appear to be discolorous (the two sides unlike in colour), and some plants have a milky latex.
This tree is browsed by elephant and black rhino. It attracts a lot of insects when in flower, including bees, ants and wasps. Pollination of the common resin bush is carried out by numerous insects that it attracts during flowering. The fruits of this plant are often highly parasitized by insect larvae that feed on the embryoin the single seed contained in the fruit; this was discovered during an observation of the population surrounding the Walter Sisulu National Botanical Garden ( Gauteng : Johannesburg ).
Pests (far left)
Insect larva feeding on seed
Top left: Fruitfly
Top right: Tachinid fly
Bottom left: Wasp
Bottom right: Bee
Uses and cultural aspects
The fruit is traditionally used to dye leather. Powdered bark from this tree is used to treat acute inflammation in the chest.
Growing Ozoroa paniculosa
The germination success rate is usually very poor with this plant. The seed should be sown immediately after removing the outer layer.
This is a fairly decorative tree even though it is not of any economic value. The leaf colour makes it a suitable focal plant in a water-wise garden.
It requires well-drained soil to grow, as well as an open area without any shade. The common resin bush is a frost-tolerant tree.
This plant often has spittle bugs on the branches from November–January, but these bugs do not cause any serious harm to the plant; a spray of water on the branches will help to remove the insects.
References and suggested reading
- Grant, S & Thomas, V. 2000. Sappi tree spotting-Bushveld. Jacana, Johannesburg.
- Pooley, E. 1993. The complete field guide to trees of Natal, Zululand & Transkei. Natal Flora Publication Trust, Durban.
- Schmidt, E., Lötter, M. & McCleland, W. 2002. Trees & shrubs of Mpumalanga and Kruger National Park. Jacana, Johannesburg.
- Van Wyk, B. & Van Wyk, P. 1997. Field guide to trees of Southern Africa. Struik Publishers, Cape Town.
- Palmer, E. 1977. A field guide to the trees of Southern Africa, edn 2. Collins, Johannesburg.
- Palmer, E. & Pitman, N. 1972. Trees of Southern Africa, vol. 2. Balkema, Cape Town.
- Nichols, G. 2005. Growing rare plants: a practical handbook on propagating the threatened plants of southern Africa. Southern African Botanical Diversity Network Report No. 36.
Walter Sisulu National Botanical Garden