The department of environmental affairs, together with its counterpart, forestry, has stepped in to try to halt the illegal harvesting of the Matumi plant around Tzaneen.
This comes after individuals and companies that were granted permits to harvest the rare plants allegedly poisoned them in an effort to harvest them quicker.
Permit holders were informed in December 2008 that they should stop harvesting the Matumi, a Breonidia-salicina, because the plant was heading for extinction.
But departmental officials said that illegal harvesting had not stopped and was continuing near Limpopo's rivers in the Mopani area.
The Green Scorpions said they have continued arresting individuals week in and week out and they were worried that harvesters were not cooperating.
Obed Moagi, from the Green Scorpions in Tzaneen, told Sowetan that the harvesters sell the plants to furniture manufacturers who use the wood to make expensive furniture.