Hunter region Landcare

Plant of the Month: Greenhood Orchid (Pterostylis nutans)

Flora, Plant of the Month, The Scoop

During winter and spring, these low green orchids, endemic to Eastern Australia, emerge from the ground in great numbers in moist, protected forest environments. The flowers “nod” or lean forwards strongly and occur singly on a stem arising from a rosette of radical leaves and may be up to 25 cm high.

This plant has a fascinating method of ensuring its successful reproduction. It emits a specialised scent to attract the mosquito sized male fungus gnat.  As the insect enters the flower, it is thrown inside by the spring loaded lip (labellum) which closes behind it.  Escape is prevented by hairs on the edge of the lip. Once inside, the insect feeds on the intoxicating nectar and looks for a way out. To do this, the insect must pass through a sticky tube and then over the pollen which adheres to it. Soon afterward, the labellum falls and the gnat is free to depart. By now, the insect has become addicted to the nectar and flies off looking for more.

Bush Tucker value: The underground starchy tubers (paired) are edible and nutritious and can be eaten raw or cooked, though as it kills the plant this is not recommended.

Image: Atlas of Living Australia