This evergreen tree was selected to be one of the Trees of the
Year for 2002. Pittosporum viridiflorum varies in size from
a shrub of about 4m in height to a large forest tree of up to 30m.
The bark is pale brown to greyish with distinctive white dots (lenticels).
The leaves are usually wider above the middle, dark green and glossy.
Small, greenish-white, sweetly fragant flowers are produced in early
summer (November to December). They are followed by small, yellow-brown
seed capsules. This plant is very showy when the capsules split
open to release numerous small, shiny, orange-red seeds, which are
covered in a sticky, resinous exudate. This cheesewood is often
confused with the white milkwood (Sideroxlon inerme).
Pittosporum viridiflorum is widely distributed in the eastern
half of South Africa, occuring from the Western Cape up into tropical
Africa and beyond to Arabia and India.. It grows over a wide range
of altitudes and varies in form from one location to another. Pittosporum
viridiflorum grows in tall forest and in scrub on the forest
margin, kloofs and on stream banks.
The name is derived from "Pitta" = pitch and "sporum"
= seed (referring to the sticky seeds); and viridiflorum
= with green flowers.
Many birds, including the red-eyed dove and several starlings
eat the seeds. Goats and game (Kudu, Nyala, and Bushbuck) browse
the leaves. The stem bark, which has a bitter taste and strong resinous
or liquorice smell, is used medicinally. Decoctions or infusions
are widely used to treat stomach complaints, abdominal pain and
fever. It is said to ease pain and have a calming effect. Dried,
powdered root or bark is sometimes added to beer as an aphrodisiac.
The wood is reportedly little used - being soft and white, which
may account for the common name - cheesewood. However, Venter&
Venter (1996) state that it is used for kitchen furniture and shelving.
According to Smith (1966), the name kasuur is a contraction of
kaasuur, candle hour, which refers to the time the flowers exude
their sweet fragrance. Smith also reports that Pittosporum viridiflorum
is cultivated on St Helena, having been introduced by the Dutch
in the 17th Century. It was also cultivated in Europe after being
introduced probably by Masson.
Growing Pittosporum viridiflorum
This plant makes a good garden plant, growing in either in full
sun or semi-shade. It makes a well-shaped, medium-sized tree or
can be pruned as a hedge. It is useful for screening and can also
be grown in a big container as a patio plant. It is hardy, neat
and undemanding and makes is an ideal plant for a small, town house
garden as it does not have a aggressive root system. Not only does
it have fragrant flowers to scent the evening garden, it is also
colourful when in fruit and attracts birds to the garden.
Cheesewood propagates easily from seed. Unparasitised seed has
a germination percentage of 80-90%. Sow seeds in trays in a mixture
of river sand and compost; cover lightly with fine compost and keep
moist. Seeds should germinate in 8-12 weeks and the fast growing
seedlings should be bagged up when they have two leaves. Plants
may also be propagated by means of softwood or semi-hardwood cuttings.
This plant transplants easily.
Pittosporum viridiflorum can withstand some frost and cold
and is fairly drought- resistant, but prefers well-drained soils
and a reasonable amount of water.
The common pittosporums in the horticultural trade come
from Australia, New Zealand and the Far East. Pittosporum undulatum
from Australia is now listed as a Category 1 Invasive Plant and
may not be cultivated in South Africa.
- Palmer, E. & Pitman, J. 1972. Trees of Southern Africa.
Balkema, Cape Town.
- Coates Palgrave, K. 1983. Trees of Southern Africa. 2nd ed.
- Van Wyk, Ben et al. 1997. Medicinal Plants of South Africa.
- Coombes, Allen, J. 1992. Guide to Plant Names. Hamlyn, London.
- Smith, C. A . 1966. Common names of South Africa Plants. Botanical
Research Institute, Pretoria.
- Venter, F. & Venter, J-A. 1996. Making the most of indigenous
trees. Briza, Pretoria.
Thompson T. Mutshinyalo
with additions by Yvonne Reynolds
Witwatersrand National Botanical Garden