Epiblema grandiflorum var. grandiflorum
A Swamp Loving Orchid of the Southwest
In mid December 2008, Graham Bowden took me on a trip to Windy Harbour on the south coast of Western Australia to photograph Epiblema grandiflorum var. grandiflorum, an orchid that is wide spread throughout the coastal strip from north of Perth to East of Esperance. For good reason has this small settlement been named Windy Harbour. Sited on the Southern ocean with its cold winter storms, this sparsely populated region has an almost constant sea breeze even on calmer days.
The handsome purple flowers of Epiblema grandiflorum var. grandiflorum grow mainly in swamps, sometimes covered in thick rushes and often with their roots in water.
It seems that they start their growth while there is standing water in the swamps, and growth continues as the stems push their way up through the water, and flowering continues as the standing water dries out through the summer. Epiblema can be seen flowering into the southern summer between November and January and, after flowering, become deciduous, resuming growth with the winter/spring rains.
Epiblema are terrestrial orchids that are endemic to Western Australia and have subterranean tubers. They have a single leaf that is almost terete and grows to approximately 30cm.
The stem grows to about 80cm to a metre tall and can carry up to 8 or more blue to mauve flowers with darker spots. (Pictured, Graham Bowden)
The flowers are up to 4cm across....
....and have a most unusual series of ribbon like appendages called calli, at the base of the labellum. The column wings form a hood over the anther. The flowers are very similar to Thelymitra but do not share the Thelymitra habit of closing on cloudy days and at night.
We noticed that the back of the flowers showed distinct colour changes where the sepals and petals had overlapped in the buds.
They grow in peaty soils in winter wet swamps and tend to form colonies.
They do not appear to require fire to regenerate but at one site, it has been recorded that 200 plants were found in each of the years 1987 & 1988 after an area was burned but fewer and fewer in succeeding years. Other factors may also bear some responsibility for that decline such as road works and housing development, etc.
Graham had been told that the Epiblema were in flower at the time so a photography trip would seem to be worth while. We left Perth at 6am, and a five hour drive south had us in the area at 11am. We needed to be away from there by around 1pm so we would be back in Perth about 6pm. This left us two hours on site in which I still managed to take around 200 pictures. Digital, naturally.
Epiblema grandiflorum var. grandiflorum were not difficult to find on the low lying coastal plain. They grew in profusion in standing water alongside the road with the flowers easy to spot as we drove along.
Close up photography dictated that we had to get our feet wet, so it was off with the shoes and, camera safely strung around our necks, we waded into the water with our toes in the muck. We were surprised at height of the Epiblema flowers above the water and estimated that many were a good metre from the soil below.
Only one species occurs in the genus Epiblema but there is another variety, (var. cyaneum) a light blue form which is currently listed as Endangered under the Federal Governments Environmental Protection and Biodiversity Conservation Act. This variety was reported to occur in only two known areas, one in a northern Perth suburb and the other at Walpole on the South Coast, but it seems there is some dispute regarding Epiblema grandiflorum var. cyaneum at the Walpole site. (See "Orchids of Western Australia" 2008 by Andrew Brown et al.)
Our own observations of the Epiblema grandiflorum var. grandiflorum at Windy Harbour showed that there is quite some variation in colour forms within a 1 kilometre range with some lighter and others darker. Their colour is difficult to describe, often being called mauve. The closest I could come to it would be blue-ish with a tinge of red-ish. You would not call them blue.
The pollinators of Epiblema are unknown at this time, but they had certainly been busy at the Windy Harbour site as many plants carried seed capsules in various stages of development. It was common to see buds, fully open flowers and seed capsules on the same plants showing that the flowers were opening in succession. A good reproduction strategy.
Many flowers showed damage, possibly caused by insects or the wind.
To the best of my knowledge, Epiblema grandiflorum var. grandiflorum has never been grown in private orchid collections, which should come as no surprise to any who have seen them in their natural environment. To duplicate the optimum conditions in your garden, though not impossible, would be difficult in the extreme. Besides, it is good to know that the future of these orchids is safer in their natural environment and they do not run the risk of becoming the subject of orchid collecting.