Hunting for orchids

Barrm Birrm has 36 recorded species of orchid, but this doesn't mean they are lined up for you to admire them. You have to look out for them, dropping your eyes to the ground, walking slowly, staying ready for their flash of colour or shape of their leaves. Patience is required, and attention to the signs of each particular orchid.

Hunting for orchids

The Wallflower Orchid, Diuris orientis, found just downslope of Princess Road, November 2022, by the Barrm Birrm Orchid Team

For orchids are individualists. Each species has its own pattern of leaves - flat and flush to the ground, or rising upwards like a spear - and each has a unique arrangement of sepals with which to catch the attention of .... no, not humans, but the native insects that will spread their pollen.

Each orchid grows up inter-dependent on specific fungi, where the orchid and the fungi each get a benefit from the relationship. Having grown out to a flower, the orchid then leaves nothing to chance, and builds a scent to attract the insect that will spread its pollen. It mimics the scent of the plant on which that insect feeds. Drawn in by a carefully concocted mix of pheromones, the wasp or bee runs into the mouth of the orchid, is coated with pollen, then is drawn on to nearby flowers to repeat its dip and dive of desire, fertilising as it goes.

The future of each orchid is therefore bound up with specific insects, the plants on which those insects feed and the fungi below ground. If those plants are cultivated out or smothered by weeds, or if the ants that move fungi around are sprayed out of existence, there goes that orchid.

So how good it is to protect that whole suite of living organisms. And hooray for the Echidna, who, foraging for ants, sends them burrowing further, making new connections underground between the fungi.

The flower catches our attention, insect and human alike, but it's like a neon sign, flashing, point to the complex set of relationships in which the orchid is embedded.

Follow links below to learn more about orchids, and download iNaturalist to see the orchids of Barrm Birrm.

Hunting for orchids

Guided by Andrew Dilley, of the Australasian Native Orchid Society, the Orchid Team has committed to track the orchids of Barrm Birrm over the next year (winter Sundays of drenching rain excepted!). Here, left to right, is Margaret, Sean, Matt, Sophie and Andrew Dilley, out in the middle of it.

Hunting for orchids

The eagle-eyed Sean McConnell found two Thelymitra aristata, last Sunday, this one right on a track. Follow the progress of the Orchid Team on iNaturalist (search for 'Barrm Birrm'). Then step out for a walk yourself, eyes peeled.