Of all the plant species found in the regional ecosystems of the Lockyer Valley, Carissa ovata is a shrub that occurs commonly throughout many vegetation communities, and I just love it! It’s a tough shrub that always looks good. The species is a member of the Apocynaceae family along with Hoya, Frangipani, Alyxia and Parsonsia, among others. As the previous species name implies, the leaves are ovate (egg-shaped), with quite a rounded edge, and they are bright green and glossy all year. There are spines which form along the stems at the nodes.
In late spring, early summer, Carissa gets covered in sweet smelling clusters of white flowers that attract a variety of insects.
What follows are the currant-like fruits which start off as green and ultimately turn a glossy black colour. They too are a food source for birds. Apparently, the fruit is edible to us, although I can’t say I’ve tried one; the milky sap that exudes from the stems is toxic, so I’m guessing that the fruit needs to undergo leaching or other treatment prior to eating.
The size of the shrub varies. Often, it has a sprawling habit and grows too about two metres in height, yet I’ve found that in some areas on the steep sandstone slopes of my property, it towers over me, reaching more like three to four metres.
There is only tank water on my property, so when undergoing any revegetation works, the seedlings get a drink at the time of planting, and that’s pretty much they’re lot until it rains. Last year I went to an area that was planted out about six months ago, to see what was still alive after months of drought. Much to my delight, the Carissa plants were lush and healthy, looking back at me as if to say, “What drought?”
Small birds will use Carissa in their flight path, travelling from shrub to shrub foraging for insects, and animals such as birds, bandicoots, snakes, and rodents can hide underneath the prickly foliage as a safe refuge. Last summer, when I was collecting fruit, I noticed a large Joseph’s coat moth (Agarista agricola) larva feeding on the foliage.
I’ve had successful germination of the seeds extracted from fresh fruit, and then soaked in water overnight. Carissa can also be propagated from cuttings in spring. It is a slow growing shrub, but so attractive and hardy – well worth the wait.