KEY POINTS:
An almost-forgotten shrub that Maori once used as a contraceptive is being studied to find out why it is declining in the North Island.
Waikato University master's student Graeme Weavers has been awarded a $23,752 fellowship by the Foundation for Research Science and Technology to help to fund his research into the genetic diversity and population dynamics of the poroporo plant, solanum aviculare, a native to New Zealand, Australia and New Guinea.
Poroporo has purple flowers and berries that ripen from green to orange, but it was the plant's leaves that Maori used for rongoa - medicinal purposes - which included treating skin complaints such as eczema, aches and pains and fertility control, Mr Weavers said.
Russia and Hungary have also used the plant's extracts for making steroid contraceptives.
But in pre-European times the leaves were boiled and then the water taken about a week before menstruation.
"I've got one cousin who remembers his mother using it as a contraceptive but many Maori don't have living memory of it. We've forgotten about it.
"An old kaumatua recognised the plant and said he hadn't seen it around since he was a kid."
That decline in traditional knowledge mirrored its ecological decline in the North Island, Mr Weavers said. Poroporo thrives on disturbed land, in areas where there have been treefall or landslides. One of the first plants to appear when trees such as tawa fall, the plants do not like too much canopy cover.
However, land clearance and pest grazing from pigs, goats and deer have done their damage, with poroporo now mainly growing in managed areas or reserves.
Mr Weavers hoped one spinoff of his research would be increased replanting projects and interest from tangata whenua about the plant's medicinal benefits.
"If we can restore poroporo populations on the scrubby open areas it likes, then the opportunity is there to utilise it locally for pharmaceutical purposes."
