Giant Devil’s Fig and Devil’s Fig Solanum chrysotrichum and S. torvum (Prickly Tobacco)

Devil’s Fig, or Prickly Tobacco as I prefer to call it, is very well known at Crystal Waters and seems to have become much more prevalent over the recent wetter years. I prefer the name Prickly Tobacco as it is very descriptive – it’s very similar to wild tobacco and it’s very prickly! Devil’s Fig is misleading as it is not a fig. The two species named above are quite similar and I think we have both here at Crystal Waters – I’ll treat them as the same for this discussion. Prickly Tobacco is not a prohibited or restricted invasive plant under the Biosecurity Act 2014, however it is a recognised weed at Crystal Waters. It doesn’t appear in the Sunshine Coast Council’s Biosecurity Plan 2024 (which you can find here), but I treat it as a “locally significant species”, with the aim of controlling and preventing its’ spread when it is impacting or threatening high value natural areas. More information on it can be found here.

Information and Identification

Prickly Tobacco originates from Central and South America and is now well established in tropical and sub-tropical areas of the east coast of Australia. It favours riparian areas and disturbed sites and seeds prolifically, with the fruit being dispersed by birds and other animals, as well as in mud carried by vehicles, etc. Dense infestations can shade out native regeneration, although it does have the advantage of providing useful shade when there’s little else and it attracts frugivorous birds. However, it’s hazardous to work around.

Identification:

• Shrub up to about 5m tall
• Deeply lobed leaves
• Lots of hairs and spines on the stems and the backs of the leaves.
• White star-shaped flowers and clusters of green fruit which turn yellow when ripe.
• Usually single stemmed, unless they’ve been cut, in which case they turn into multi-stemmed monsters!

Impacts

Considered an environmental weed in parts of Qld and NSW. Possibly poisonous to stock and can cause injuries to stock and humans.

Distribution at Crystal Waters

Pretty much everywhere! Especially in riparian areas and wetter sites which get disturbed.

Control methods and efforts

We have been working on reducing the impact of this weed in plantings and along walking tracks. Cutting and dabbing with glyphosate seems to be quite successful – most plants seem to die after one treatment. Just cutting off the plants without treating them is counter-productive – the plants grow back bigger and better, with many stems, so they’re much harder to deal with then. Small ones can be easily pulled out when the soil is moist. I’ve also experimented with ring-barking a couple of very large ones – I’ll report back on that later.