Wander along the tracks in the Grampians at this time of year and look down. Among the leaf litter, beside mossy rocks, and under the open canopy of stringybark and messmate, small green rosettes are pushing through the soil. They are easy to walk past — flat, neat little circles of leaves no bigger than a 50-cent piece. But they are the first sign of one of the park’s most extraordinary plant groups returning for another season: the greenhood orchids, genus Pterostylis.
According to VicFlora, “about 250 species, mostly endemic in Australia but also occurring in New Guinea, Ceram, New Caledonia and New Zealand; about 82 species and 3 named hybrids in Victoria.”
These are terrestrial, perennial herbs that survive the long dry summer as a single fleshy underground tuber. As the days shorten and the autumn rains arrive — which is exactly what is happening across the Grampians now — the tuber sprouts and pushes up a rosette of leaves. Flowering comes later, usually weeks after the leaves first appear.
What the leaves tell you.
One peculiarity of many greenhoods is that flowering and non-flowering plants look quite different. Non-flowering plants of species like Pterostylis nutans, the Nodding Greenhood, sit as a flat ground-hugging rosette of three to six ovate leaves with wavy or crisped margins. When the same plant flowers, the rosette often disappears — replaced by a stem-leafed flowering spike. The leaves you are seeing now will not necessarily produce a flower this season. Many tubers spend several years in vegetative form, building reserves, before flowering.
The Grampians is one of the richest orchid areas in Victoria, and a handful of Pterostylis species are particular to it. Which ones will you find this year?
To find out more this is a great book from Orchid expert Gary Backhouse
https://blog.publish.csiro.au/native-orchids-gary-backhouse/
Pterostylis ampliata Southern Autumn Greenhood
Pterostylis rubescens Blushing tiny greenhood