Is this a Weed – Elderberry Panax (Polyscias sambucifolia)? By Karen Hising

One of the most common questions I am asked as a Bushcare Officer: “Is this a weed?” And quite often the person asking the question is referring to the native Elderberry Panax (Polyscias sambucifolia).

Polyscias sambucifolia is a variable small to large shrub or sometimes even a compact tree. The leaves are compound, with clusters of succulent bluish-grey fruit in Summer.

An important colonising species in regenerating areas, it can appear as a single plant or in small dense forests before other species have the opportunity to regenerate. At Blackheath Centenary Reserve, where all large shrubs and trees have been removed for powerline safety, swathes of Polyscias have appeared over time and have shaded out groundlayer and grassy weeds. Fortunately, it has not grown too tall to warrant removal under the powerlines – yet!

This plant also provides feeding opportunities for local wildlife. Birds enjoy feasting on the fruit, which is how it is widely propagated. The Elderberry Panax Leaf Roller (Cryptoptila australiana) can infest the whole plant in swathes of webbing. The larvae live in a communal shelter made of leaves joined with silk and feed on the foliage. They are dark-brownish green, with orange spots and white hairs. Pupation occurs within the larval shelter. The plant can look quite bedraggled from the impacts of these insects, but they generally bounce back once the caterpillars finalise their lifecycle to moths and move on. Birds may also enjoy feeding on these larvae.

Whilst it may not be considered a particularly attractive plant (particularly when covered in webbing), it can be an important part of some ecosystems.

Polyscias – from the Greek word, poly, meaning many, and skias, meaning shade, possibly referring to the shade from many leaves; and sambucifolia – referring to leaves which resemble Sambucus, the Elderberry.

There is some debate pronouncing the genus name – poly-sy-as or pol-is-kias