By: Sharyn Kann

One of the local orchids my bushwalking friend has been telling me about, is the Pterostylus nutans or Nodding Greenhood, a terrestrial orchid I have been keen to see.  Finally, a phone call confirmed that they are out in flower and he was happy to take Len and me on a walk to see them.

Leaves

Nodding Greenhood Orchid leaves

On the high side of the track of the bush reserve was a cluster of several Nodding Greenhoods, some in flower and some yet to flower.  Had I seen them without the flower, I would never have picked the plant as an orchid.

 The first photo here shows the plant itself without a flower spike.  The leaves grow flat to the ground in a basal rosette and the plant has a small underground tuber.  To my untrained eye, they looked like a lot of the other plants growing on the forest floor.

Nodding Orchid

Cluster of orchids in flower

This next photo shows most of the cluster of Greenhoods with their long stem and single blossom.  As you can see, they don’t actually stand out much, blending quite well into the background.

Of the 78 or so named species found in Australia, New Zealand, New Caledonia and Papua, the Nodding Greenhood is probably the most common, occurring in all states, except maybe, Western Australia.

130502_0016_02

Nodding Greenhood flower with insect inside

Greenhoods are generally fertilised by insects who land on the strap like hinge of the labellum.  They are then flung into the hood with their only escape being the up the tube formed by the closed labellum and the column wings.  At the outlet, the insect has to press past the pollinia where their sticky viscid disc adheres to its back.  As it repeats this process with other greenhoods, the sticky disc on its back is pressed against the stigma beneath the column wings of the next plant and more pollinia is attached as it proceeds out of the flower.

The hood is a soft semi-transparent apple green colour, and insects inside it can easily be seen.

Photos by Sharyn Kann and Alan Moore, with information taken from Australian Native Orchids in Colour by Leo Cady & E R /Rotherham.

Brisbane Orchid Society meet regularly at the refurbished Progress Hall, Upper Mt Gravatt – 4th Monday month at 7:45Pm.