Having featured two of our Helmet Orchids over the past two months, it seems discriminatory to ignore Corybas incurvus Slaty Helmet Orchid, the most common and widespread of our Helmet Orchids, which is flowering in many places at the present time.
Large colonies of Slaty Helmet Orchid leaves can often be seen in cool, damp and shady places in gullies, coastal scrublands and heathlands. The leaves are light green, ground-hugging and rounded, with a prominent central vein. There are usually many more leaves than flowers. A single, reddish-purple flower appears to rest on the leaf – there actually is a very short stem. The flower is dominated by the dorsal sepal and the labellum. The slaty coloured dorsal sepal is hooded over the labellum, which is widely flared with a central white mound and finely toothed strongly incurved margins.
The first of our Diuris species to flower each year is the Diuris pardina Leopard Orchid, which is now being seen in many places. The flowers are yellow with red-brown blotches, and appear to mimic the pea flowers that often grow nearby.
Both the pea flowers and the orchids attract pollinating bees, but in contrast to the orchid that provides no reward, the pea flowers offer both nectar and pollen. However the visiting bee, as it endeavours futilely to find nectar in the orchid flower, either removes or delivers pollen to the tiny column of the orchid.
Acianthus caudatus Mayfly Orchids are now also flowering, and many of the heart-shaped leaves, dark-green above and purple below, can be seen in the heathlands and open forests. They are held above the ground.
These orchids, too, have an interesting means of pollination. Fungus gnats visit the purple flowers that have long, slender sepals. These flowers have copious nectar that stupefies the insects while they are feeding, allowing plenty of time for the pollinia to stick firmly to the insect’s back, and which can then be carried to another flower. The flowers emit a strong, foul smell on warm days, and this attracts a high level of insect activity.
There are many other orchids to observe as you walk the bush tracks – still plenty of Greenhoods to admire, and many of our spring orchids are in bud. Hopefully some gentle rains and warm sunshine will encourage their growth. Please share your orchid finds with us.
References: 2010, Flora of the Otway Plain & Ranges 1, Orchids … , CSIRO PUBLISHING;
Foster, Everett & MacDonald, Margaret (ed) 2009, Orchids of the Anglesea District, ANGAIR Inc., Anglesea