Elegant Donkey Orchid - Diuris concinna
This can be a tall orchid, growing close to 60 cm (2 foot) in height as it struggles to protrude above the slender stemmed sedges where it commonly grows. However it is much shorter after fire when it does not have to compete, and may in these circumstances be only 20 cm (8") in height. In these conditions it more than makes up for the lack of height by the brightness of the often densely packed colonies.
I have only found it in and around swampy areas, often growing in regions recently flooded. Flowering time is from late September to well into November. In dry seasons it may not or rarely flower at all. Due to the late flowering period, habitat and larger flower (30 mm or over 1"), plus the general plant size it should not be confused with other local Diuris species.
Update 4/10/08
A couple of colonies were discovered on a sandy mesa-like top over 10 metres above a creek. The sand was very deep and a mixture of acid and alkaline particles. On the other side of the creek (the south side) the soils are alkaline, and around 200 metres to the north, they are acid. Probably over the centuries, when bushfires had denuded the ground of vegetation, strong winds would have blown sand from either soil type to create this mix, although currently thanks to prevailing south-westerly winds, the soils are probably more alkaline.
The orchids were growing in the shelter of spaced 3-4 metre high Calothamnus quadrifidus shrubs (One-sided Bottlebrush), which reduced the growth of other shrub species, thereby leaving a reasonably open and sunny lower story environment. This habitat could not be described as moist, but was sheltered from drying winds.
Elegant Donkey Orchid - Diuris concinna
