Four species of small but beautiful Helmet orchids (Corybas sp.) grow in the Anglesea District.
All species are tiny, deciduous, terrestrial orchids that remain dormant during the dry summer months as small, rounded tuberoids beneath the soil surface. The onset of autumn and winter rains will see the orchids producing a single, circular to heart-shaped leaf that is close to the ground. They often form large colonies. The tiny flowers (to 25 mm) that will follow, can usually be seen in bud as the leaves emerge. Helmet Orchids are thought to be pollinated by fungus gnats, slender mosquito-like insects. The flowers have no detectable odour, but is has been suggested that their shape and colour mimic the fungi that gnats visit to lay their eggs. The gnats enter the flower through a tiny opening (auricle) at the base of the flower.
Corybas unguiculatus Small Helmet Orchid is the first of our Helmet Orchids to appear each year, with leaves usually being observed in May. It is an uncommon species in the district, but over the past few years, some excellent colonies have been observed at Moggs Creek. These orchids are flowering as I write this article. The leaf is heart-shaped, and the reddish-purple flower is drooping. The tip of the labellum protrudes beyond the dorsal sepal – this feature distinguishes it from the rare species, C. fordhamii, which also grows in the district.
Small Helmet Orchid
Corybas diemenicus Veined Helmet Orchid is perhaps the most attractive of the four species. It has a textured, heart-shaped leaf. The dark red flower opens on top of a stem to a height of 20 mm. The labellum is flared, with toothed margins and a white central mound. Tiny buds have already been observed this year in our known colonies. It is a rare orchid, growing in restricted areas, and should flower in late July to August.
Veined Helmet Orchid
Corybas incurvus Slaty Helmet Orchid usually flowers a little later than the Veined Helmet Orchid, and is the most common of our four species. Large colonies of hundreds of leaves can often be seen growing in damp, shady positions. Tiny leaves are just starting to emerge through the soil. The reddish flowers appear to squat on the leaf. The labellum is strongly incurved around the white central mound.
Slaty Helmet Orchid
Corybas fordhamii Swamp Helmet Orchid is very rarely seen, as it only grows in swampy areas often along with Melaleuca squarrosa Scented Paperbark. It flowers in September, with flowers similar to those of C. unguiculatus, but the dorsal sepal projects well over the striped labellum.
Swamp Helmet Orchid
There are many other orchids to keep a watch for – Greenhoods, Mosquito Orchids and Gnat Orchids should all be flowering during July and August.
Photos and descriptions of all of these orchids are documented in Orchids of the Anglesea District available from Angair.