Another New Orchid (for me) - Bunochilus tunstallii

On the same trip as I reported yesterday, with Alan and Kirsten from ANOS Illawarra. Alan took us to where this Orchid grows. It is Bunochilus tunstallii.

Botanical Illustration from PlantNET

It is clearly in the group of "Tall or Leafy Greenhoods", named after the primary member of that group to be named, Bunochilus longifolius.

Botanical Illustration from PlantNET

All these Bunochilus plants were formerly known as Pterostylis, and owing to the rules of scientific naming, they now have masculine endings to their specific names, whereas previously they were feminine species names ("ia" ending, changed to "ius" ending).

This particular species (B. tunstallii) was first described from the area where Alan showed it to us. This is its "type locality". In fact it is very restricted in its distribution, roughly from near Robertson, down onto the coast below Nowra (where we saw it), and there are possible records from further south in NSW. Interestingly Colin Rowan (Retired Aussies), who has photographed this species in the same area as my record, also reports this species from Wilson's Promontory, Victoria.

The main differences in these two (closely related) species is apparent when the flowers are compared closely. Tunstall's Greenhood is much darker in the labellum, whereas the Tall Greenhood (B. longifolius) not only has a dark stripe on the otherwise light labellum, but it is also notably spiky along the edges of the labellum (Clearly visible on the image below). Apparently there are also internal differences in the structure of the hood, but I cannot comment on those details.

Click to enlarge the image.
B. longifolius compared with B. tunstalliiHere is B. tunstallii seen from the side.
A very small flower, with a particularly dark labellum.
This plant was growing some distance (several kilometres) away
from the main colony of B. tunstallii plants.
Here is another flower viewed from more directly in front.
This next flower has a story, in that Alan had inspected the flower closely, and proclaimed that it was indeed the species we were looking for (B. tunstallii). It was the first plant of this species which we had found.

Alan then took some photos as did Kirsten. Then as I got down to photograph it, I realised there was a grass leaf in the road,
between my camera and the flower.
I removed the grass leaf, and in so doing I shook the plant, and the movement sensitive labellum was "triggered".
The labellum snapped closed.
This commonly happens when photographing these Leafy Greenhoods.
So, for the record this image shows the
underside of the labellum (in its closed up position).
This image shows that the underside of the labellum is dark in B. tunstallii.