Until recently I have never done any work with orchids, so they have been a bit of a mystery to me. I didn’t know where they were, what they looked like, when they flowered, or what their general biology was. I guess I’ve been waiting for an opportunity to spend some time finding this out…and now I finally have!
My new job as an environmental consultant has thrown me into a number of different situations that are at the foreign to me, one of those being a project on native terrestrial orchids in Victoria. What a perfect excuse to get out, take lots of photos, and learn about this fascinating group of plants.
Many native orchids produce very few leaves (often only one!) so they can be extremely difficult to spot when they are not flowering. They make up for this lack of showiness with some of the most spectacular and unique flowers you will ever see. Spring is a great time to catch many of these orchids flowering, so now’s the time.
There are hundreds of species of native orchids known to occur in Victoria, so I will never see them all. But, there are a few key groups that make up some of the more common ones you are likely to find. Here is a collection of some of my favourites that I’ve stumbled across the past few weeks in Western Victoria – I really hope to keep building this collection over time.
The basic structure of an orchid flower is 3 sepals and 3 petals, but the basal petal ‘labellum’ and dorsal sepal in particular are in many cases highly modified to create an astounding diversity of forms. Most of the terrestrial forms are geophyte monocots meaning they ‘die off’ after the flowering season and regrow from below-ground tubers the following season.
Thelymitras (Sun orchids), or Thelys, are common in Victoria and are a well-known feature of Victorian orchids. They come in an amazing range of colours and sizes, all stunning. They are referred to as Sun-orchids due to their flowers opening and closing depending on the sun (tip: best to spot them on a sunny day). Generally speaking, Thelys have one leaf and a small tuber; their flowers have symmetrical arrangements (petals and sepals look the same); and they can be insect or self-pollinated.
So here we arrive at some of the more diverse and spectacular flowers. Caladenias (Spider orchids) have a very similar vegetative structure to Thelys, i.e. similar size, shape, and having a single leaf. But the flower shape almost couldn’t be more different (in particular the labellum that is distinctly different to the other petals/sepals). The structure and function of each flower is different and the pollination strategies of each one is far too complex for this blog.
Despite being one of the most inconspicuous orchids, due to its green flowers (Greenhoods), this is probably the genus most people will see in real life. The dorsal sepal arches over the rest of the flower giving it its green hood. Pterostylis species tend to have larger tubers, which indicates a potential to live for a long period and resist difficult growing conditions. Many of these orchids have a hinge on the labellum which flicks up inside the hood when touched – the idea being to ‘catch’ insects in there making it more likely that they will pick up the pollen.
…and a few other gems.
Here is a collection of some others that I’ve seen that will give a flavour of some of the other types not covered in the lists above. Glossodia (Waxlip orchid), Diuris (Donkey orchid), and Calochilus (Bearded orchid).
The orchid season is coming to a close soon so although I’m hoping to see a few more of these amazing plants in flower, I might have to wait until next year for many of them. But I’ll be ready for them!
If you are really keen on Victorian orchids, you might want to head to the Victorian Native Orchid Society website.