Replanting the Combretum caffrum


In early 2004 the Combretum caffrum, Cape Bushwillow or South African Willow, was removed due to extensive decay and decline in the health of the tree. For many years the large weeping tree, possibly planted in the 1930s was a feature of the western boundary shrubbery of Victoria Gardens. This tree was about half way along the boundary and just near the drinking fountain.

Stonnington Council attempted to propagate the bushwillow but were unsuccessful. Contact was with David Robbins of the Royal Botanic Gardens in October 2004 to propagate the tree. Again it proved a difficult species to propagate and all 15 semi-hardwood cuttings failed. In February 2005, 20 softwood cuttings were taken from a very old tree which fell over in a storm at the south end of the Hopetoun Lawn. Only one cutting was propagated. In February 2006, 20 more cuttings were taken and 2 cuttings grew roots. These were grown on over the next 2 years and one of these was planted in Victoria Gardens on 19 December 2008.

The tree was about 1.5m high and the planting was undertaken with the assistance of staff from Stonnington Council and in front of several Friends. The replanting was the final event to celebrate the 21st birthday of the Friends of Victoria Gardens.

In 1988 there were 8 Combretum caffrum trees in the Royal Botanic Gardens. Today there are just 2 trees, and 2 in the nursery that are to be planted in the Gardens. There are 6 other Combretum species including the red flowering climber Combretum bracteosum (Hiccough Nut)

John Hawker, Jenny Legge, Ann Bishop, Bill Forster, Peter Legge, Kevin Ryan & Georgina Whitehead.

John Hawker, Jenny Legge, Ann Bishop, Bill Forster, Peter Legge, Kevin Ryan & Georgina Whitehead.

Other known trees in Victoria occur at;
Caulfield:
Caulfield Park, 3 trees along Inkerman Road
Greenmeadow Gardens, Trunk circumference 2.2m, height 13m, Canopy spread 16.5m (1983)
Prahran:
Princess Gardens, Trunk circumference 1.8m, height 7.5m, Canopy spread 13.2m (1988)
Victoria Gardens
Hopetoun Gardens, Elsternwick
‘Barragunda’, Cape Schanck
‘Holey Plain’, Rosedale (young tree, replaces old removed tree)
‘Strathfieldsaye’, Perry’s Bridge (Stratford), 2 trees

Combretum caffrum, Cape Bushwillow or South African Willow
A tree to about 10m tall, bark grey to pale brown, leaves opposite, narrowly elliptic, 5-10cm long, 1-1.5cm wide. Flowers axillary, greenish yellow in short heads 1.5cm wide. Fruit reddish, 1.5cm long with 4 wings. The tree grows naturally along the coast of the East Cape of South Africa in damp areas and along watercourses. Though somewhat reminiscent of willows (Salix), they are not close relatives.

The bushwillows or Combretum, make up the type genus of the family Combretaceae. The genus comprises about 370 species of trees shrubs and climbers, roughly 300 of which are native to tropical and southern Africa, about 5 to Madagascar, some 25 to tropical Asia and approximately 40 to tropical America. Australia has one species.

Bushwillow trees often are important plants in their habitat. Savannahs in Africa, in particular those growing on granitic soils, are often dominated by Combretum and its close relative Terminalia. Other species of this genus are a major component of Southwestern Amazonian moist forests. This genus contains several species that are pollinated by mammals other than bats, which is quite rare indeed. But most species are more conventionally pollinated by insects or birds.

Several species are used in African or Indian traditional medicine. Combretastatins, found in the South African Bushwillow (C. caffrum) and presumably other species of this genus, are under study for the therapy of tumors, including anaplastic thyroid cancer for which there is little or no approved treatment at present. At least C. molle is also recorded to contain large quantities of punicalagins, the antioxidants well-known from the Pomegranate (Punica granatum), a somewhat related plant. These chemicals are suspected to suppress cancer growth. An extract from the bark of Combretum caffrum was used as poison by Zulu warriors, is used as a general tonic, and now shows promise for cancer treatments. A variety of anti-cancer compounds called combretastatins are found within the tree bark, the most potent of which is combretastatin.

John Hawker
Friends of Victoria Gardens
5 June 2009