Chance discovery triples critically endangered plant population

The delicate ‘terminal’ white flowers and fleshy leaves of Galium antarcticum, which grows amongst mosses and grasses on Macquarie Island.
The delicate ‘terminal’ white flowers and fleshy leaves of Galium antarcticum, which grows amongst mosses and grasses on Macquarie Island. (Photo: Alex Fergus)

A new population of a critically endangered plant species has been discovered on sub-Antarctic Macquarie Island, tripling the previously known population to some 1500 plants.

The tiny, herbaceous Galium antarcticum (‘sub-Antarctic bedstraw’) was recently discovered by chance at Skua Lake, near the central west coast of the Island, by Monash University PhD student Cath Dickson.

Ms Dickson and fellow botanist, Dr Alex Fergus from the Department of Conservation New Zealand, surveyed the area and found 1000 healthy individuals within a 15 m radius, many in flower.

Galium antarcticum is tiny, generally less than 50 mm long, and grows in association with moss beds, making it easy to overlook,” Ms Dickson said.

The plant was first sighted on Macquarie Island in 1982. In 2013, following the dramatic reduction in rabbit numbers as part of the pest eradication program on the island, botanists rediscovered a population of about 500 plants at the original site on the north-west side of Skua Lake. The new plants were discovered in March (2017) on the southern side of the lake. The species only grows on a few sub-Antarctic islands and in Patagonia, South America.

“This is a very exciting and significant discovery. I look forward to checking on the health of the plants when I return next year and hope that the team can collect some seeds to further secure its survival,” Ms Dickson said.