This very aggressive weed (Solanum chrysotrichum) is establishing quickly in SEQ and North NSW. In some areas it is already the dominant understorey plant while in other areas like Tallebudgera Valley where we live, it is spreading really quickly. Related to wild tobacco, the fruit is almost identical to that of wild tobacco and was immediately accepted by fruit eating birds. Each single fruit contains lots of seeds, which germinate readily. There were only a few individual specimens in our valley just a few years ago, but now we are removing several hundred seedlings a year from our 3ha property.
It will grow almost anywhere, including dry rocky eucalypt country, and in time will likely pose a serious threat to wildlife like Koalas. This species should have been classified as a declared weed years ago.
The plant grows to about 6 metres tall, is a very quick grower reaching 2-3 metres in the first year. It flowers and fruits in the first or second year.
The trunk is covered in very sharp thorns, even at the seedling stage. The flowers are white and grow in clusters. The leaves are very large and lobed. After a few seasons lots of offspring will have grown around the original parent plant and these can form dense stands with stems less than one metre apart, forming an impenetrable wall of thorn covered stems.
This species is not easy to kill by application of foliar herbicide. It is best to cut the stems with loppers or a saw near to the base of the trunk and apply neat Glyphosate (e.g. with a paint brush) to the cut within 15 seconds. If the tree is larger it is safer to cut off the upper branches first. A larger tree can be very heavy and spikey when it falls. Heavy gloves and protective clothing are highly recommended.
Please do your bit to reduce the spread of this species.