The Cherry Ballart Exocarpos cupressiformis is a unique tree but looking at it many people aren’t aware of its peculiar nature.
Known as a hemiparasite (or semi-parasite) it needs other plants, particularly Eucalypts and to a lesser extent Acacias, in it’s earlier stages of life. This is due to it parasitising the roots of these plants and obtaining nutrients and water from them. Once they become mature Cherry Ballarts can photosynthesize by themselves and therefore don’t need other plants as much. The stems, not the leaves, perform the majority of this photosynthesis as the leaves are reduced to scales, not unlike Sheoaks Allocasuarina spp.
Scientists are still perplexed on some of functions of this plant and one of these is how it germinates. Horticulturalists have found that propagating the seed with Kangaroo Grass Themeda triandra or the introduced Lucerne Medicago sativa, both of which have been passed through the stomach of hens, have produced some success. It has also been found that they are probably reliant on mychorrizal fungi so placing soil from it’s natural habitat in the propagation mix may be also beneficial. It does however regenerate very well from cut or damaged stumps and sends out multiple suckers.
The Cherry Ballart was first discovered in 1792 by the French naturalist Jacques-Julien Houton de Labillardière while exploring southern Tasmania as part of Admiral Bruni d’Entrecasteaux’s command of the two ships Recherche and Esperence. Labillardière named it Exocarpos, Exo meaning external, carpos meaning fruit. This is due to the fact that the actual fruit, a small inedible nut, is found at the end of a yellow to red succulent swollen pedicle or stalk. This swollen stem is often mistakenly referred to as the fruit and is very delicious but small in size.
The Cherry Ballart with its very dense and light green canopy is a very prominent tree in a variety of wet to dry habitats, usually but not always in association with eucalypt woodlands or forest. Its distribution extends along the eastern parts of Australia from Qld to SA, including Tasmania. This plant can be a powerhouse in terms of providing protection and a food source for a massive variety of wildlife as well as herbs and grasses. Small birds in particular find this ideal protection to forage and build their nests. The fruit-eating birds in summer also have a plentiful supply of succulent berries on which to feast on. I have seen Silvereyes en masse as well as Satin Bowerbirds foraging on the fruit in summer. Insect-eating birds also feed on the often abundant insect and spider fauna associated with the plant.
Insects and other invertebrates also find this tree ideal habitat and there are some species which specialize in Cherry Ballarts such as the Crexa moth Genduara punctigera whose caterpillars feed only on the leaves of Cherry Ballarts.
The brightly coloured Stink Bug Commius elegans also has a penchant for this plant and in mid summer the trees can be loaded with the bug and its newly hatched nymphs. Both the adults and the nymphs feed on the leaves and stems of the Cherry Ballart with the adults remaining near the young until they are older.
I have also seen Ring-tail Possums using the dense foliage to build their dreys and on hot summer days it’s not uncommon to see a kangaroo or wallaby sheltering from the sun under the thick canopy of the tree. Unfortunately deer, particularly Sambar and Red, also have a liking for this tree and will heavily browse the lower branches. Males frequently rub their antlers on the trunk in the rutting season and this damage has been found to reduce the density of Ballarts as well as other trees and shrubs in an area.
The Cherry Ballart is a unique and significant tree in the forests and woodland of eastern Australia and one which shows a great resilience to a wide range of soil and climatic conditions.