Our Bushland Diary

Sunday, September 20, 2009

'tis the season for Orchidaceae...

September seems to be "the" season for orchids. Western Australia has over 700 species of orchids. In contrast to orchids found in other areas of the world, the ones in the south-west are all "ground orchids" - they have an underground tuber or root system in the soil, and are ephemeral (i.e. they like to frustrate botanists and photographers by disappearing back into the soil when they have finished their pollination cycle.) Compare this with tropical and sub-tropical orchids, which are found all year round, growing on trees or cliff-faces, as climbers or epiphytes.

All Western Australian orchids are protected by law.

Hunting for orchids can easily become an obsession. They can be difficult to find, because of their "here today, gone tomorrow" lifestyle. On many occasions, I have visited a place where I found a nice photogenic orchid a week earlier, and do you think I can find it again? Sometimes it's because they are tasty and the wildlife can't resist having a bit of a chew... other times because the flowers last for only a few days.

The plants are dormant for most of the year, and leaves generally pop out of the soil in late winter. Even so, they are easily overlooked, and almost impossible to identify to species level, until they are in flower. They have gorgeous flower colours and shapes, but are so small that getting a focus on them is taxing, therefore they are fun to photograph!

Above: a greenhood orchid, from the genus Pterostylis. I think it's Pterostylis sanguinea. It doesn't have a common name in wide usage. "Sanguinea" refers to the blood-red stripes, but having a common name such as "Blood-red Greenhood" would be too weird.

Above: the Purple Enamel orchid (Elythranthera brunonis). This orchid, with its glossy surfaces, is a little shining jewel in the understorey. The back of the petals are white with purple spots, a bit of a "faux fur" pattern. This species has a cousin called the Pink Enamel orchid. (Guess what colour that one is?)

This photo, above, is of a Leek Orchid, in the genus Prasophyllum. This one is probably the Autumn Leek Orchid, Prasophyllum parvifolium.

A beautiful white orchid, above, the white version of the Pink Fairy Orchid (Caladenia latifolia). The more usual colour is a light pastel pink, the colour of a strawberry milkshake, with the little fringed section in the middle white.

This, above, is one of the easiest orchids to identify, and one of the most widespread throughout the south-west of WA. It's the Cowslip Orchid (Caladenia flava). (Yes, I know that the flowers are "upside-down" but that's how they were in the bushland.) There is wide variation in the colouring; some orchids have no red at all, some are very yellow, some very "faded" to off-white. I wonder how many kids in Ellenbrook are familiar with this flower?

This one, above, is a strange looking little creature, isn't it? It's called a Flying Duck Orchid. The scientific name is Paracaleana nigrita. These orchids grow in patches of grey sand on the edges of Melaleuca wetlands. Oh, there's that funny pink background* again.

Last photo, above, is Pheladenia deformis. It has no common name, but I would love to call it the Cool Violet Orchid because it flowers in winter, earlier than most other orchids, and of course because of its colour. The area that I found this orchid is now a construction site. Fortunately, this species has a wide distribution, so I know for sure that wasn't the last one on earth.

One amazing thing about these orchids is that none of them need the European honey bee for pollination. Instead, orchids are pollinated by orchid wasps and other indigenous insects.

Hopefully all these species, and many others, will continue to live in our bushland remnants in Ellenbrook, as well as the nearby Bush Forever sites.

*If you're wondering why there is a hand in the photos, there are two reasons. One is that it's usually a wet windy day when I go orchid hunting, and secondly that the orchids are small and I like to use centred autofocus to get a fix on them... so it helps to have my hand behind them as a wind-guard and close background for the autofocus. Usually I get down on the ground to take photos of orchids. So, it's dirty work on a wet day. It's funny how many people have stopped to help me "look for something" when they see me searching diligently near a roadside! But, thankyou...

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