The flower of the underworld
Status: In Serious Decline, Threatened - Nationally Vulnerable
The wood rose (Dactylanthus taylorii) is Aotearoa’s only fully parasitic endemic flowering plant, which is aptly represented in it’s Māori name, Pua o Te Rēinga: the “flower of the underworld” (Ecroyd, 1996).
This “flower of the underworld” was named due to the species spending most of its life underground. This makes it very difficult to get an actual estimate on the number of Dactylanthus surviving in Aotearoa (Wood et al., 2012). The Dactylanthus is thought to attach itself to the root of a number of different native and non-native plants including Mahoe, Tarata and Putaputaweta from which it takes nutrients (Ecroyd, 1996). The result of this parasitic relationship is the development of a wooden rose moulded into the root of the host plant, which alludes to it’s common name (Ecroyd, 1996).
Dactylanthus is a treasure that you would be very lucky to stumble across, as it’s distribution is now extremely limited to only a few North Island sites (Holzapfel, 2001; Wood et al., 2012). The decline in abundance has been caused by introduced species such as rats and pigs which eat or trample the plant, as well as humans who have been known to collect and sell it (Ecroyd, 1996; La cock et al., 2005). Possums remain the biggest threat because they enjoy eating the flower, preventing the plant from seeding and therefore reproducing (Ecroyd, 1996).
One of the places the Dactylanthus can still be found is the summit of Mount Pirongia in the Waikato, where a volunteer group from Pirongia Te Aroaro o Kahu restoration society has been working hard to protect the species (Priongia, n.d.). The work includes locating and recording the species, placing cages around them to protect them from pests and sometimes pollinating the species.
Natural pollination of Dactylanthus is mostly done by one of our two endemic native mammals, the short tailed bat, attracted by the strong scent of the flower (Cummings et al., 2014; Czenze & Thurley, 2018). However, unfortunately, the overlap in habitat between the short-tailed bat and Dactylanthus has become increasingly uncommon (Wood et al., 2012). Despite this, the wood rose gets top marks for its ability to flower, so should pollination occur there are plenty of seeds to distribute.
What you can do to help:
If you live in Hamilton or the Waikato area and want to get involved in protecting the species, join the Pirongia Te Aroaro o Kahu restoration society. These guys are doing great work monitoring the population of the species, recording new individuals and building cages to protect them. If this isn’t an option then simply familiarizing yourself with the species and keeping an eye out when you go walking and recording when and where you see individuals is very helpful for monitoring their distribution and abundance in Aotearoa. In particular, DOC is very interested in populations in the Waitakeres, the South Island, Northland, Whanganui, Great Barrier Island and Wellington. If you ever see wood rose for sale, in markets or online, or people digging up the species, report it to DOC so we can protect one of our most unique species from extinction!
Cummings, G., Anderson, S., Dennis, T., Toth, C., & Parsons, S. (2014). Competition for pollination by the lesser short‐tailed bat and its influence on the flowering phenology of some New Zealand endemics. Journal of Zoology, 293(4), 281-288
Czenze, Z. J., & Thurley, T. (2018). Weather and demographics affect Dactylanthus flower visitation by New Zealand lesser short-tailed bats. New Zealand Journal of Ecology, 42(1), 80-84.
Ecroyd, C. E. (1996). The ecology of Dactylanthus taylorii and threats to its survival. New Zealand Journal of Ecology, 81-100.
Holzapfel, S. (2001). Studies of the New Zealand root-parasite Dactylanthus taylorii (Balanophoraceae). Englera, 3-176.
La Cock, G. D., Holzapfel, S., King, D., & Singers, N. (2005). Dactylanthus Taylorii Recovery Plan, 2004-14. Department of Conservation.
Pirongia Te Aroaro o Kahu Restoration Society (n.d.). Dactylantus. Retrieved from https://www.mtpirongia.org.nz/dactylanthus
Wood, J. R., Wilmshurst, J. M., Worthy, T. H., Holzapfel, A. S., & Cooper, A. (2012). A lost link between a flightless parrot and a parasitic plant and the potential role of coprolites in conservation paleobiology. Conservation Biology, 26(6), 1091-1099.