Hiding in plain sight – the common orchid you can go decades without seeing
A COLONY OF unusual orchids at a Perth reserve is flowering in the thousands after producing nothing but foliage for more than a decade.
The orchids, known as red beaks (Pyrorchis nigricans), are widespread throughout south western WA, and can also be found in parts of New South Wales, Victoria, Tasmania, South Australia and the ACT. Although they are common, red beaks usually only flower in response to a scorching by a summer fire.
After a small fire at Perth’s Wireless Hill Park in March, one colony has flowered en-masse, adding red beaks to the list of orchids that can be spotted at the urban wildflower hotspot this spring.
Most years people only see elephant ears
A close-up of a red beaks orchid. (Photo credit: Shannon Verhagen)
Andrew Brown, the coordinator for threatened flora at the WA’s Department of Parks and Wildlife and a taxonomist specialising in orchids at the WA Herbarium, says that while the red beaks are quite common, most years all you’ll see are their big, succulent leaves.
“Most years they come up as these big leaves called ‘elephant’s ears’ colloquially,” he explains. “Occasionally they’ll pop up one or two flowers, but most years it’s just the leaves.”
“People can watch these colonies for years and years and not see a flowering plant.”
The colony at Wireless Hill has not flowered for over a decade – and another Perth population is not known to have flowered in the last 50 years. However, Andrew says that somewhere in the Perth region a colony will flower each year, depending on where bush has been burnt.
The red beak’s scientific name ‘Pyrorchis’ means ‘fire orchid’, however it’s just one of about 32 orchid species in WA that flower following a fire.
The reason these orchids flower is due to a chemical reaction, says Andrew, “We’re still not 100 per cent sure what ingredient stimulates it – but the reaction produces ethylene gas and there are also chemicals in the smoke that provide extra nutrients that seem to promote flowering.”
No need for flowers
The red beaks are one of about 32 orchids found in WA that flower in large numbers following fire. (Photo credit: Shannon Verhagen)
While many plant species require flowers to reproduce, red beaks are able to reproduce vegetatively – a form of asexual reproduction where the parent plant can produce genetically identical daughter plants without cross-pollination from other flowers.
Andrew says this is why they are often found in large colonies, like the one in Wireless Hill.
“Red beaks are colonial – all of the flowers in that colony probably come from one original seedling,” he says.
“They have a tuber and that tuber sprouts annually producing a leaf and several lateral root-like structures with additional tubers, each of which can produce a new plant.”
“So it doesn’t need to flower very often.”