Journal Number 106
December 2007

A New Discovery of the Rare Sun-Orchid,
Thelymitra matthewsii on Kangaroo Island
By D.A. (Andy) Young - From Nossa Journal October 2007.

I have great pleasure in announcing to N.O.S.S.A members the discovery of the rare and enigmatic orchid, Thelymitra matthewsii or the spiral sun-orchid. More excitingly, perhaps, is the fact that the find is of what would appear to be a stable colony. The find was made by Kangaroo Island botanist Bev Overton and Trish Mooney, the Bush management adviser for the K.I. Department of Environment and Heritage. The location is being kept secret, to aid in the preservation of the colony, however it can be revealed that it lies within a conservation area on the north coast of the Island and the plants are growing along a cleared path within an area of Eucalyptus shrubland, on a lateritic soil.

Having previously been shown Trish's photo of the two plants in bud that Bev and her had initially noted, on Tuesday the fourth of September this year, I accompanied Trish and Dave Taylor, Threatened Species Officer for the K.I. Department of Environment and Heritage, along with Sarah Jones of DEH, to do a quick survey of this site for further plants. I was of the opinion that having two plants growing adjacent to each other of this rare species was exceptional.

On arrival at the site I was hoping that a wallaby or goat hadn't decided to have a quick bite at our expense and have made the journey out to the location a waste of time. Sure enough, the plants were still present, though one had suffered a chewed bud. This allowed a peek at the beautiful mid purple colour exposed at the base of the chewed dorsal sepal. While photographs of the budding plants were being taken, Dave noted a small spiral leaf just adjacent to the plants we were looking at. Before long all members of the party were searching along either side of the path and over the next forty minutes twenty-two plants were found. Four plants, including the original two, were in bud.

All of these plants were growing along a stretch of track about 30-40 meters long, within a shallow depression at the top of a hill. The specific bush block had not been burnt for some time, however it may be significant that a section of bush close to the site had burnt recently and the area would have been subjected to quite a considerable amount of smoke during this event. The burn area was uphill from the area, so water that would have gathered in the hollow would have been tainted by burn products. While paths in the general area were quickly surveyed, the soil type and character of the area where the plants were located was found to be quite distinctive and no further plants were observed.

As it has been noted, to avoid any interference of this exceptional site, the number of people "in the know" is being kept to a minimum. There has been a consensus that some D.N.A leaf clips will be taken from the flowering plants once seed has been successfully set, but that photographs should be sufficient to confirm the presence of this distinctive species, and therefore a voucher specimen is not necessary in this case. The possibility of attempting to actively restrict access to the site and of promoting further expansion of the colony is being explored.

How exciting!!!