Survey Finds More Siam Weed

July 28, 2017

Airborne siam weed seedA week of intensive surveying has found more Siam weed around the edges of Tinaroo Falls Dam. We’re calling on the community to help identify the source of infestation and prevent further spread.

The Department of Agriculture and Fisheries (DAF), SunWater, and Queensland Parks and Wildlife Service coordinated the survey after a recent Siam weed detection by a botanist fishing on the dam.

Boat and foot patrols were used to spot the weeds, which were then removed. The survey was timed before the plants had set seed.

Dave Green from DAF said that the size of some of the weeds indicated they have been there for several years. “At present, the survey effort has yet to identify where the infestation started. Finding this out will be the focus of our activities in the coming months, and will determine how we manage this weed into the future.”

While not known where the infestation started, it's possible there are larger infestations in the upper reaches of the creeks flowing into Tinaroo dam, or that the seed was transported to the area on a vehicle or boat. The weed appears to have been in the area for some time, which is somewhat concerning however treatment has already commenced.

Siam begins to flower in June, and will have set seed by now so keep an eye out for seeds which are brown to black, 4-5 mm long with parachute-like tufts of white hairs. One plant can produce up to 80 000 seeds. The distinctive triangular shaped leaves with veins in a three-pronged pitchfork pattern can also help identify the weed.

Siam grows predominantly as a shrub, but can also grow in a vine-like structure up to 10 metres high when in dense forest.

Siam can have health impacts and cause skin complaints and asthma in allergy-prone people. It is also toxic to cattle and can take over pastures and crops. Siam can impact the waterways and recreational areas of Tinaroo dam.

Take action

To enjoy the area responsibly, and stop the spread of invasive weeds, make sure you Come Clean, Go Clean. Wash all shoes, cars, boats, canoes, skis and trailers before you come, and immediately when you leave.

Siam weed is controllable, especially with the support of the community. Please check your property, especially if you live upstream from the dam and report anything that looks like Siam to Tableland Regional Council on 1300 362 242.