This month’s winner was Jenny Pauley’s photograph of a Corybasincurvus (syn Corysanthesincurva).
Before looking specifically at the species, it might well be worthwhile looking at the features that distinguish the Corysanthes (Toothed Helmet Orchid) group from Corybas (Spurred Helmet Orchid). The major difference appears to be in the flowers. The Corybas flower is dominated by the dorsal sepal which hides the labellum whereas with the Corysanthes the dorsal sepal and labellum are equally prominent although sometimes the dorsal sepal may be the less dominant. A less obvious difference occurs in the leaves. Corysanthes leaves have a fine point but this is absent in Corybas. Based on this only Corysanthes (Toothed Helmet Orchid) occurs in South Australia.
C. incurva, as part of the Corysanthes group, is interesting because the flower does not appear flared or toothed. But though the labellum curves in, it does initially start to flare, and it does have fine short teeth. In fact, in the early stages of the flower opening it can be possible to confuse it with the opening bud of C. diemenica. One of the differences between these two species is that the flower of C. incurva sits on the leaf with no clearly visible stem whilst C. diemenica is raised above the leaf with a visible stem.
This image of a typical Corybas from Colin Rowan, retiredaussie.com , helps to see the difference between Corysanthes and Corybas.
This image of C. diemenica (syn Corybas diemenicus) is a good comparison. Note the difference between the stems.
Anzybas unguiculatas (common name Little Pelican or Cherry Helmet Orchid) was the main focus for this month’s competition with three photographs of this diminutive flower.
The other photographs were Ed Lowrey’s close-up of a triggered Urochilus sanguineus labellum, John Badger’s first Diuris palustris sighting for this year and Pauline Meyer’s mass flowering of Leptoceras menziesii post fire. Of the Anzybas, Jenny Pauley entered two and Lorraine Badger one. Jenny Pauley’s photograph of two flowers was the outstanding winner.
Originally named Corysanthes unguiculata (1810), then Corybas unguiculatus (1871), the genus name was changed in 2002 to Anzybas in recognition of its distribution both in Australia in New Zealand. Since 1945 it had been recognised that the New Zealand species Corybas cheesemanii was a synonym for Corybas unguiculatas although the juvenile plant can have two leaves unlike the Australian species which is single leafed.
An interesting feature of this flower is the prominent white ears at the rear of the helmet (not clearly seen in this photograph) which are part of the labellum.
An unusual aspect of this photograph is that the colour of the underside of one of the leaves. It lacks the characteristic distinguishing feature of the purple underside of the leaves. According to orchid growers, the light affects the leaf colour. Heavy shade produces green leaves. It is possible that the heavy leaf litter where this plant was growing provided enough deep shade to cause the colour loss.
Bates (1990) states that it (has) not proved amenable to cultivation, but it has, on rare occasions, been benched at NOSSA meetings with the most recent occurrence was in July 2010 but it remains a very difficult plant to cultivate. The electronic version Vol 34 No 7 has a photograph of the plant just visible within the moss.
It is not always easy to photograph this species as not only is it rare with limited numbers but there are very few sites where it can be found. Added to that is that the window of opportunity is short in South Australia with a flowering time from June to August compared with those interstate which can range from May to October.
There has always been an interest in Australian orchids. Over the years there have been many photographs of orchids. This stereographic postcard from 1928 is a study in beauty –
This postcard is held by the State Library of Victoria.
Although the distribution covers the Southern Lofty, Kangaroo Island and the South East regions of South Australia, it has become increasingly rare due to loss of habitat which consists of leaf litter on damp soils. As a result, there are very limited localities where they can now be found.
It is one of our earliest helmets to flower which is from June to July.