Noogoora Burr – Xanthium strumarium
Habit: Woody herb to 2m. Rough leaves and dries off annually. Fruit is a spiny woody burr with 2 brown-black seeds inside.
Spread: Seeds spread in waterways and catch onto animals, people and cars.
Noogoora Burr has spread prolifically throughout the lower Fitzroy catchment. Flood waters recede after each wet season, leaving behind masses of seed and a carpet of newly germinating Noogoora burr along river banks, adjoined billabongs and tributarys. This photo was taken in February 09 at Duckhole (an anabranch of the Fitzroy River)
It is important to be able to recognise new germinants of most weeds. By being able to identify Noogoora Burr at the seedling stage (above), control measures will be able to be implemented earlier. Land managers can then act quickly and avoid reducing the safety, efficiency and effectiveness of the weed control program as the plants get bigger and begin to produce burred seed that catches on everything!
As the plant matures the leaves take on their distinctive shape and texture (rough). The leaves stalks also become reddish.
By the mid-late dry season, Noogoora Burr has dried off, leaving behind many hooked burrs containing seed. These seeds are easily transported in flood waters, catch on to stock, vehicles and native animals.
The burr casing provides the seed of Noogoora Burr with some protection from fire and increases the longevity and viability of the seed in the soil. Burning may activate the germination of Noogoora Burr and therefore assist with an almost immediate flushing of the soil stored seedbank. Any burning should be followed up with further control activities in the early germination phase of the plant.