A new population of healthy Dactylanthus (wood rose) was found on a property in Rangitīkei.
A new population of healthy Dactylanthus (wood rose) was found on a property in Rangitīkei.
A rare endemic plant species found only in New Zealand’s North Island has been discovered at a Rangitīkei property after the success of predator control efforts.
The plant, Dactylanthus taylorii – more commonly known as pua o te reinga or wood rose, is New Zealand’s only fully parasitic flowering plant.
“It invades the roots of its host species and forms rhizomes, which it uses to get nutrients from the host,” Horizons Regional Council senior biodiversity adviser Dr Zoë Stone said.
“The name wood rose refers to the unique flower-like formation which the host plant forms when Dactylanthusattaches to its roots.”
Stone located the new population of wood rose during a routine visit to the Rangitīkei property, a surprising find because of the location.
“Most populations of Dactylanthus in our region are found in and around the central plateau, so finding a population this far south is really exciting,” she said.
“It may seem like a small discovery but these little wins are really rewarding. It means the actions we’re taking to help to give our native biodiversity a fighting chance are making a difference.”
The property where the species was found is biodiverse and actively managed under Horizons’ Priority Habitats Programme.
The programme aims to restore and maintain a range of the Horizons region’s indigenous ecosystems that remain on private land by managing and reporting on sites in the programme, and assessing new sites for the scheme.
“The site contains a rare fragment of critically endangered rimu, mataī and hīnau forest,” Stone said.
“Only 3% of this ecosystem remains in the region. As part of the Priority Habitat Programme, Horizons works with the landowners to help protect this rare forest fragment.
“On this property, we have active old man’s beard control and possum control programmes under way, which support forest regeneration and improve protection of native birds, reptiles and invertebrates.”
Stone said the landowners were excited to have wood rose found on their property and were actively working with Horizons to help protect the plant.
The pekapeka (short-tailed bat) is the key pollinator of dactylanthus (wood rose). Photo / David Mudge
“The relationship between the two species is vital for its survival,” Stone said.
“Our biodiversity protection work through our Priority Habitats Programme helps to address some of these issues but, without intervention, these plants would likely not survive.
“We’re now planning to monitor for pekapeka on the property to see if they are present. If there is no active population, we may need to give the plant some help with hand pollination.”
“Possums are attracted to the sweet-smelling blooms when Dactylanthus is in flower, causing damage to the plant and interrupting its ability to set seed. As a result, many populations are slowly declining,” Stone said.
One of the best ways to protect wood rose from possums was by placing cages around the plants, she said.
“The cages stop the possums from being able to access the plants, while still allowing pollinators access. It’s important for the future of the species to protect this process.
“Finding so many live specimens of Dactylanthus is possible evidence that the possum control measures in place are working to reduce possum populations in the area.”
Additional funding to expand Horizons’ possum control operations had been earmarked for the 2025-26 Annual Plan, Horizons biodiversity, biosecurity and partnerships manager Craig Davey said.
“To keep up the gains, it’s key to continue funding and expanding the network so we don’t lose this momentum,” he said.
“This significant investment will enable us to expand our current network of 210,000 bait stations and expand into at least four new areas of the region that were previously controlled by Ospri.“
Ospri is a not-for-profit company working in partnership with primary industries and the Government.