'Trad' (the author abbreviation of John Tradescant) is the the weed species Tradescantia fluminensis (also known as T. albiflora). While two privet species are the most important woody weeds, trad presents a big challenge for control on the forest floor. This is because it can cover the ground in a thick mat that prevents the regeneration of rainforest seedlings. It also competes with four species in the same family, Commelinaceae, that are native to Ourimbah Creek. These native species are Aneilema acuminatum, Aneilema biflorum, Commelina cyanea and Pollia crispata.
Fortunately, our trad does not set seed (it is probably a self-sterile clone) and therefore, once it is removed from any specific area it doesn't come back unless re-introduced. This is the basis for the success of the methods outlined below.
Where trad isn't growing as a thick mat, it can be weeded by hand. Be sure to wear gloves (surgical gloves are best for delicate weeding), because trad sap can cause an allergic response. There are also a few points to watch out for.
Trad grows in damp, shady places as a thick mat. Unless you are fond of lost causes, don't try to hand weed large areas of such thick monocultures. An effective strategy is to attack the mat in the following stages.
The long term method
Trad grows well in partially-shaded and moist areas - just the kind of places that would, in its absence, regenerate rainforest. But even trad has its limits. It does not thrive under the deep shade of a mature rainforest canopy. So, take comfort from the fact that, in the long term, your forest itself will become resilient enough to resist this terrible weed.
A trad 'corral', in which we dump hand-weeded trad for spraying with glyphosate herbicide. The plastic bags are needed because of male brush turkeys. They will scatter a pile of weed, apparently mistaking it for a nest made by a rival. Alternatively, they will incorporate it into their own nest pile. Fortunately, their instinctive behaviour doesn't seem to cope with plastic tree guards!
Before you kill it, have a close look at a trad flower. Around the stamens you will see some fine hairs. Under the microscope (photo below), these are seen to be strings of cells, so transparent that you can see mitochondria streaming along strands of protoplasm.
Photo Michael Reid
You can see protoplasmic streaming in this video - worth a visit to see how lively those floral hairs of tradescantia are.
Our trad is sterile
Fortunately for us, our trad does not set seed. This may be because it was introduced into Australia as a self-sterile clone. There is always the danger that another clone could arrive to pollinate and set seed with our resident clone - seeding forms have been found in the Chatham Islands.
If that happened to us, that would make trad an even more serious weed.
More information can be found from the following link:
The potential for biocontrol of trad is being investigated in New Zealand. Three beetle species from SE Brazil, where trad is a native plant, appear to show promise. One of these eats the foliage (Neolema ogloblini), another the growing tips (Neolema abbreviata), while another eats the stems (Lema basicostata),