White spider orchid, Caladenia longicauda
Plants I love

Orchid hunt

I’m on an orchid hunt in south-west Western Australia. Our quarries are tiny, delicately detailed ground orchids. Of the thousand species of ground orchids in Australia, almost half are found here. It’s not just orchids that are over-represented here either. The numbers of plant species is boggling: more than 8000 different flowering natives, with more being discovered every year.

I’m on the southern edge of the region, in the Stirling Ranges, and I only need to look at my feet to appreciate that diversity. Around me I count at least 12 species before being distracted. That’s a pretty pathetic effort. Botanists typically find 25 species in a 10m by 10m quadrant in the south west, with the record being 110, in Lesuer National Park north of Perth. I gave up counting when I noticed a twining, twinkling sundew. These carnivorous plants catch insects in sticky ‘dew’ that sparkles like a ring of diamonds. Sure enough, when I lean close enough I see a tiny green wasp trapped, and slowly being absorbed into the plant.

But we’re not here for the micro brutality of the sundews. John Byrne is leading us to orchids. Byrne jokes that he farms cattle, crops and caravans on his Mount Trio property. The caravans started turning up in when he set up a bush camp for travellers on the wildflower trail and he now offers guided walks every morning.

This morning we are heading for an old gravel pit worked in the ‘60s and never remediated. The orchids grow where the topsoil was scraped into mounds. Most obvious are glowing communities of cowslip orchid, Caladenia flava.

Cowslip orchid, Caldenia flava

Cowslip orchid, Caladenia flava, is the most common of WA’s spider orchids. It often grows together in colonies in which all plants are clones of each other. 

Nearby are the shiny enamel orchids, Elythranthera emarginata, glossy as a freshly painted fingernail, and white spider orchids with long trailing petals.

Enamel orchid, Elythranthera emarginata

Purple enamel orchid, Elythranthera brunonsis. The backs of the petals have a fantastic snake-skin pattern.

They are highly desirable and not coming to a garden near you any time soon. These plants have exceptionally specialized growing requirements evolved over millions of years in infertile soils. The adaptations are bizarre. Each orchid species must be infected with a specific fungi that supplies carbohydrate in exchange for water, nitrogen and phosphates.

White spider orchid, Caladenia longicauda

White spider orchid, Caladenia longicauda.

As well as specific fungi, the ground orchids have evolved with a specific pollinator, and many cheat and lie to lure them in. The spider orchids, for instance, emit a perfume that smells like the pheromone a particular female wasp uses to signal sexual availability. To double the deceit, part of the flower looks like a female wasp. The deluded male flies from flower to flower transferring pollen in a fruitless search for a sexual partner.

Dancing spider orchid, Caladenia discoidea

Dancing spider orchid, Caladenia discoidea

Our hunt is more successful than that of the hapless pollinator wasps. We spot a dozen of the 54 different species John has identified on the property. All have a fragile appearance and a fascinating story, going part way to explaining why some orchid hunters are driven to collect the full set.

Heberle's spider orchid, Caladenia heberleana

Heberle’s spider orchid, Caladenia heberleana. Just look where this is growing!

***Exciting news!
I’m leading a garden tour of Holland and Belgium next spring with Viking cruises. We’ll enjoy the ease and comfort of a river cruise, (love that unpack once thing!) with plenty of great garden moments at the height of tulip season. It will be just a small group and we’ll have a ball. Read the full itinerary on the brochure:
Spring blooms with Robin Powell


2 thoughts on “Orchid hunt

  1. kay berry says:

    Hi Beautiful site photos are so clear i have a real job taking photos of orchids, would you be ably to give me a hint on camera you use, we live in Mingenew have found a good few around here, orchids are my favorite wild flower, regards Kay

    • Robin Powell says:

      Hi Kay, I use an Olympus OM-D E-M5. One great thing about the camera is that it has a moveable display at the back so that I can use that to see what I’m taking without having to lie down on the ground and look through the viewfinder. Most of the new digital cameras offer this I think. When you’re taking pictures of tiny orchids you’re really best to use a tripod and a macro lens, so you can get right up close, but I was on the run when I took these pictures, so no time for a tripod – I just used my zoom. Hope that helps.

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