Dactylanthus taylorii, commonly known in English as wood rose and in Māori as ("flower of the underworld"), is a fully parasitic flowering plant, the only one endemic to New Zealand. The host tree responds to the presence of Dactylanthus by forming a burl-like structure that resembles a fluted wooden rose (hence the common name). When the flowers emerge on the forest floor, they are pollinated by a ground-foraging species of native bat.

Description

left|thumb|Dactylanthus taylorii in flower

Dactylanthus taylorii is a round, warty, tuber-like stem (up to 50 cm wide) or haustorium with no roots, which draws nutrients from the roots of its host. Its leaves do not photosynthesise, and are reduced to floral bracts. It is illegal to collect wood roses from public land, and harvesting this threatened species is strongly discouraged. The genus name is derived from the Greek (dáktulos), “finger”, and (ánthos), “flower”. and claimed the Māori name for Dactylanthus was waewae atua, "feet or toes of the spirits/gods".

The closest relative of Dactylanthus is Hachettea from New Caledonia. Along with Mystropetalon from South Africa, they comprise the Southern Hemisphere group Mystropetalaceae. All three are holoparasites, lacking chlorophyll, and are descended from hemiparasitic root parasites, which could photosynthesise.

Reproduction

Plants are dioecious, either male or female, and only rarely hermaphrodites. They flower between February and May Male flowers produce nectar that provides a simple but very sweet fragrance which promotes bat-pollination.

Analysis of fossil coprolites suggest the kākāpō (Strigops habroptilus), a flightless nocturnal parrot, was also a pollinator. Pollinated plants produce fruits slightly under long. Introduced mice and rats also pollinate them, although rats tend to destroy them.

Distribution

Dactylanthus is currently found only in the North Island, although there is evidence from fossil pollen it lived recently in the northern South Island. It also lives on Little Barrier Island. Ngā Manu Nature Reserve in Waikanae has two established, flowering sites as well as two sites added in 2021. The wood rose is under threat from harvesting by collectors, browsing by possums, rats, pigs and deer, habitat loss, and the rarity of its pollinators and seed dispersers. Control of the browsing mammals that feed on Dactylanthus, especially possums and kiore, is one conservation strategy. Another is to enclose the plants in protective cages. Because cages also exclude the plant's pollinators, its flowers then need to be hand-pollinated, and the resulting seed set turns out to be no better than in uncaged plants. Dactylanthus has recently been successfully translocated in the wild by sown seeds in closed-canopy forest.

In May 2025, a wild population of Dactylanthus was discovered in the Wainuiomata Water Collection Area near Wellington. The species had been thought to be extinct in the Wellington Region for over a century. A management plan will be prepared to assist in preserving this wild population.

References

  • New Zealand Department of Conservation Dactylanthus information
  • Radio New Zealand: Our Changing World programme about Dactylanthus, with photographs, audio and video.
  • Dactylanthus discussed on RadioNZ Critter of the Week, 19 February 2016