New weed jumps the fence


with Brownie

AS responsible gardeners, we all have a duty of care to make sure that what we grow in our patch, doesn’t become a problem for someone else.

Of the more than 2,500 weeds affecting our environment across the country, around two-thirds of them have escaped from gardens.

Every year, a handful of new plants are found to have jumped the fence and become established into areas that they have never been found in before.

Just recently, the first ever recording of a new environmental weed was made in the Coolum area.

Queensland Parks and Wildlife rangers found an unusual tree growing within the Mount Coolum National Park. It turned out to be a garden ornamental called the Autograph Tree (Clusia rosea).

The Autograph Tree is a small, crooked-trunked tree reaching about 8m tall, with very large and conspicuous dark glossy green, paddle-shaped leaves. When broken, stems and leaves exude a copious yellow sap that hardens into a resin-like substance that is mildly toxic.

The tree is named from the curious fact that leaves can be written on using a pencil, and the resulting message remains like green calligraphy on the living leaf.

Ping-pong ball-sized buds develop into large pink and white flowers (up to 8cm across), becoming large fruits, splitting to reveal many reddish seeds. Larger trees can produce aerial roots, rather like a Pandanus does.

The rangers have found and removed over 20 plants from within the national park and surrounds, all of which have grown from seed originating in local backyard gardens.

Overseas, the Autograph Tree has shown its pest potential, invading coastal areas in the Hawaiian Islands of Maui, Oahu, Kauai, and the Big Island, and has become weedy in some Sri Lankan ecosystems. There is also evidence of weediness in parts of South Africa.

The species is problematic, as it can germinate high in the forks of trees, and become almost epiphytic, sending down roots that eventually strangle the host tree. This arboreal habit makes it difficult to detect and control.

Many people are now looking for this newly invading plant species across coastal Queensland, and the Sunshine Coast Council is considering whether the Autograph Tree should be added to their list of ‘locally significant’ invasive plant species under their Biosecurity Plan.

Early detection and control will prove vital in preventing this species from potentially becoming as widespread as it is in parts of the Hawaiian Islands.

If you think you have this tree in your garden or believe you might have seen plants locally, become a ‘weed spotter’ and report it to Council on 5475 7272.

Don’t forget that if you’ve got a question or would like to ask me something, send an email to
reception@gcnews.com.au. I’d also love to see photos of anything special you’ve got in your garden.

Advertisement