Two species of Gnat Orchids grow in the Anglesea District, Cyrtostylis reniformis Small Gnat-orchid and Cyrtostylis robusta Large Gnat-orchid.
The Small Gnat-orchid is widespread through heathland and open forest, while the Large Gnat-orchid is more isolated, and is mainly confined to coastal areas. Both species reproduce vegetatively, and also from seed, forming large colonies of rounded, ground-hugging leaves, with mostly non-flowering plants. They are deciduous terrestrial orchids, dormant as small underground spherical tuberoids in summer, with growth commencing following the onset of autumn rains. Flowering commences in winter, and both species are flowering at the present time.
At first glance it may be difficult to distinguish between the two species, but there are obvious differences. As the name suggests, Cyrtostylis robusta is a larger and stronger species than Cyrtostylis reniformis – the leaves are larger, the flower stem is usually taller, and the flowers are also larger and more numerous.
Cyrtostylis robusta has a bright green leaf to 50 mm across. It also has a network of veins on the upper side of the leaf (a distinguishing feature between it and Corybas species), which is lighter below.
Large Gnat-orchid leaf
The labellum is 15 mm x 6 mm and has a short pointed tip on its apex.
The flower stalk can bear up to seven, reddish-brown flowers.
Cyrtostylis reniformis has a grey-green leaf to 30 mm across, which is heavily veined and also lighter below.
Small Gnat-orchid leaf
The labellum is 10 mm x 4 mm with a ragged or rounded apex. The flower stalk usually bears one to four brownish flowers.
It is thought that both species are pollinated by gnats and small flies. The orchids do offer a reward to visitors, with nectar running down the labellum from glands at the base of the column.
Other Orchids to Look For
There are other species of orchids to catch your eye as you wander about – Helmet Orchids are flowering, Nodding Greenhoods and Trim Greenhoods are also in flower.
Tall Greenhoods are in bud, and rosettes of other greenhood species can be observed.
Yellow and brown Diuris pardina Leopard Orchids should be flowering shortly, while leaves of our spring-flowering orchids Thelymitra and Caladenia are starting to appear. We just need some rain and some warm weather to encourage their growth.
It is an exciting time to be out in the field making discoveries as you explore the various areas. Please let us know of your findings.
Photos and descriptions of all of these orchids are documented in Orchids of the Anglesea District available from ANGAIR.