When walking along bush tracks in the National Park or other reserves, it is easy to walk past some of our low-growing terrestrial orchids, without, indeed, noticing them.
One of these species, which is flowering at the present time, is Corybas unguiculatus Small Helmet Orchid. Growing among leaf and bark litter, and humus under bracken, sedges, grasses and shrubs, finding these tiny reddish-purple, drooping flowers peeping out from the ground litter, either as an individual plant or growing in a colony, is an exciting experience.
The flower stem is short and slender, just about 10 mm high, and the dorsal sepal and the labellum of the orchid form an open tube. The dorsal sepal is hooded over the labellum, but does not cover the broad labellum tip. The ground-hugging heart shaped leaves (30 mm long x 20 mm wide) are grey-green above, and either green or purplish below.
They are thinner in texture than those of the Mosquito Orchid Acianthus pusillus. Two other species of Helmet Orchids, Corybas diemenicus Veined Helmet Orchid and Corybas incurvus Slaty Helmet Orchid, should also be appearing in July.
It is thought that fungus gnats pollinate all species of Helmet Orchids. The orchids have no detectable odour, but it has been suggested, as their shape and colour mimic certain types of fungi, that the gnats visit the orchids by mistake to lay their eggs, and thus assist pollination.
Winter is also the time when we look for Greenhoods - Pterostylis nutans Nodding Greenhood, P. concinna Trim Greenhood, P. curta Blunt Greenhood, P. nana Dwarf Greenhood, P. sanguinea Banded Greenhood, P. melagramma Tall Greenhood, and possibly P. chlorogramma Green-Striped Greenhood. We were excited to find a new colony of P. striata Striped Greenhood flowering in Aireys Inlet, but unfortunately these are on private land.
Cyrtostylis robusta Large Gnat Orchid is also flowering, and Cyrtostylis reniformis Gnat Orchid is in bud. Leaves of many of our spring flowering orchids are also starting to appear.
Photos and descriptions of all the orchids that grow in the Anglesea district are documented in Orchids of the Anglesea District available from ANGAIR.