Following on from the article on Cockspur Thorn (Maclura cochinchinensis) in the July 2015 edition, we continue the thorny theme with another prickly customer, Barbed-wire Vine or Smilax (Smilax australis). Like Cockspur Thorn, this is another native vine very common to most environments across South East Queensland. It is found anywhere from littoral rainforests to open eucalypt forests and even in heathland.
A day in the bush wearing shorts often seems to result in scratched and bloody lower legs. Smilax is usually the culprit and is a good reminder to wear appropriate clothing! Despite this, I still sometimes wear shorts in the height of summer only to pay for it with scratches that sting for a number of days. Perhaps a small price to pay for spending a pleasant day in the bush?
Although there are some annoying points (pun intended) to this and other spiky vines, they are hugely outweighed by the positives they provide in their environments. Smilax alone provides habitat for many different species. Its round black fruit are eaten by birds such as the Satin Bowerbird and Green Catbird, while the leaves are food for caterpillars of the impressively-named Erebus Moth (Erebus terminitincta) and three species of butterfly: the Fiery Jewel (Hypochrysops ignita), Bright Forest-blue (Pseudodipsas cephenes) and Coral Jewel (Hypochrysops miskini).
Smilax in flower
A scrambling thicket of Smilax
Shiny, black Smilax fruit
Clusters of individual cream-tubular flowers of Smilax attract a myriad of insects, especially butterflies. Most importantly, like all of its other spiky friends, Smilax provides great cover and protection for many animals. Its ability to form impenetrable thickets makes it an ideal hiding and nesting place for birds, particularly Eastern Whipbirds. Smilax also scrambles through and over small bushes and shrubs, providing great shade with its large leathery leaves. Wallabies make good use of such spots on hot days.
These spiky vines sometimes get a bad rap when they interrupt a peaceful walk through a bushland property. But every native plant has its role in nature, no matter how big or small (or annoying) it may be. My advice for those who dislike these thorny locals is to trim, tie back or re-direct the vines away from access tracks, particularly where they are at face level. Away from tracks, vines should be left alone to do what they do best – scramble and climb throughout the bush.
If you are weeding, then wearing shoes, long pants, a long sleeve shirt, gloves and safety glasses are a good way to avoid being scratched. If you treat these spiky vines as friends not foes, your local fauna will definitely thank you for it.
Article and photographs by Cody Hochen Land for Wildlife Officer Brisbane City Council