Possums put flower power to test

An endangered native Taranaki plant is being kept under a cage and closely watched by the Conservation Department while it is in flower.

The department has fenced off nearly 200 dactylanthus plants, also known as a wood rose, in Egmont National Park to prevent attacks by hungry possums.

"One possum can prevent a whole population from reproducing by munching the flowers before they have the chance to set seed," biodiversity ranger Jack Mace says.

The dactylanthus is New Zealand's only completely parasitic flowering plant, depending on host plants like horopito, kamahi and toro for sustenance.

It grows as a root-like stem attached to the root of a host tree

The host root moulds into the shape of a fluted wooden rose and through this placenta-like attachment the dactylanthus draws all its nutrients.

The plant is pollinated by rats and mice. They carry the pollen from the flowers on their whiskers.

"Our cages let them through. The horrible little pests are a necessary evil," Mr Mace says.

DACTYLANTHUS

* Has no green leaves or roots of its own.

* Has a strong scent.

* Separate male and female plants.

* Found only in NZ.

* Grows almost completely under the ground.

* Threatened by possums, rats, deer, goats, pigs and stock.