By Mark Dunphy, Vice-President of Big Scrub Landcare.
The tall trunk and lush foliage of the Nightcap Oak (Eidothea hardeniana) is striking, but not easy to spot. A member of the Proteaceae (Banksia and Grevillea) family, it’s so rare and well hidden that it wasn’t discovered until 2000, and with only around 100 adults left in the wild you really need to know where to look to find one.
But that will hopefully start to change for this ancient tree. The first planting of Nightcap Oak seedlings has been carried out in a secret location in Nightcap National Park with 20 young trees introduced. Botanist and bush regenerator Darren Bailey and NSW Government’s Saving our Species Project Officer Justin Mallee planted the trees in a location chosen to keep them safe from fire and people.
This planting represents one of the first steps towards saving the ancient species. Its vulnerability was highlighted during 2019’s Black Summer fires, which burnt into areas of Nightcap National Park. When the fires went out, our worst fears were confirmed with the discovery a significant number of mature Nightcap Oaks were burnt.
With only 100 adults and 84 juveniles left in the wild, the Nightcap Oak is as rare as the Wollemi Pine, which numbers 41 adults and 200 to 300 juveniles in the wild and is the subject of extensive restoration efforts.
The vulnerability of the Nightcap Oak is compounded by all 184 residing in a single creek catchment, all within a couple of kilometres of each other. It is an ancient species, with fossils found in Ballarat linking it to species that existed 15 to 20 million years ago on Gondwana. Yet, to our knowledge, only this tiny footprint remains.
A recovery plan was written in 2004 to work towards the survival of the species. Part of the plan is to collect seeds from the ground, propagate them in a nursery and plant them in locations (ex-situ) that have similar geography but would be more likely to survive another fire event.
The recently planted saplings germinated from seed collected in February 2020, when about 500 fruits were collected. A low germination rate was observed with only 10% or 50 individuals germinating, confirming a lack of seed viability as one of the main reasons behind its scarcity.
Interestingly, another reason for its scarcity is its palatability. Rodents love to gnaw through the thick shell and eat the macadamia-like nut. Very few seem to escape the jaws of hungry native rats.
Even with these challenges, the Nightcap Oak has survived longer than most. It is our hope that these efforts and the steps in its recovery plan will see this towering emergent survive long into the future.