For our first group of the year, Rebecca Hosking kindly supplied us with frozen samples of fruiting Coastal Ballart, Exocarpos syrticola.
Fruit of Coastal Ballart, exocarpus syrticola, with purple drupes on enlarged receptacles. Photo, Rebecca Hosking
This is not native to our area and Flora of Victoria’s key to the genus Exocarpos, as well as much group discussion, revealed some interesting similarities and differences between our local Cherry Ballart, Exocarpos cupressiformis, and Coastal Ballart:
- The flower spike is much shorter in Coastal Ballart
- Both species have small alternately arranged scale-like leaves of similar shape
- The fruiting parts provided the definitive difference, Coastal Ballart having a white to pink enlarged receptacle to which a smaller purple fruit is attached, clearly very different to the orange/red enlarged receptacle and green fruit of the Cherry Ballart.
The fruit structure of these species is often not understood; the fruit is botanically known as a drupe (think stone fruit) and will contain one seed. The drupe sits on top of an enlarged floral part known as the receptacle, which is the end of the flower stalk to which the flower parts are joined.