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Horizon

Ground Orchids

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I have to share these.

These are three awesome ground orchids found growing in the national park behind my mothers place.

None of which have been seen in our area for a very long time.

All three were found in a very small area. Not all of the orchids were flowering but there were thousands of them that have shot up their leaves.

They are a deciduous plant that lives below the ground over the hotter months, that will send leaves above ground over the cooler months and when the conditions are right will send up flowers.

The first one is a

Helmet Orchid Corybus barbarae

Mosquito Orchid Acianthus fornicatus

Nodding Greenhood Pterostylis nutans

Hope you enjoy

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Sorry the pics came out back to front

The one on the far right is the helmut orchid

Middle one is still the mosquito orchid

And the one on the left is the nodding orchid

Cheers

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These are flowering across the NSW North Coast too. A lovely scene on the forest floor.

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The Corybus is a good find. Very nice :)

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That corybas barbarae is awesome... Its a shame we don't get that species down here in the southern states. Seeking out orchids is a great way to hone into the microcosms that surround you in a forest. Its really good to have people here that have an appreciation for these plants. Many species are having a hard time in Australia coping with significant environmental changes such as land clearing, grazing, soil disturbances, weed invasions, etc. etc.

These plants are an indicator species, usually if you find terrestrial orchids, you know you are in a healthy environment. For a terrestrial orchid to survive, it needs the presence of a symbiotic fungi. These plants exchange photosynthetic plant-derived carbon in return for soil nutrients such as nitrogen, phosphorus, vitamins and amino-acids . Some terrestrial orchids are not very selective in which species of leaf-mold fungus they pair up with, while others are highly selective. There is a species of spider orchid in WA that relies on a fungus that can only survive on the roots of a particular fern species (If theres no fern, theres no fungus, and thus no orchid).

Probably the most amazing thing about these little guys is the relationship they have with pollinators. This facinated Charles Darwin so much so that he spent two months in Torquay (South of Geelong on the Great ocean road,VIC) studying the relationships between orchids and their pollinators.

For most of the year, the orchid is dormant, and nothing but a small potato like tuber is found underground. The only real interaction they have with the outside world is a flower that they send up once a year if conditions are suitable. Although some terrestrial orchids are mostly anemophilous (pollinated by wind) or have general pollinators such as native bees, the majority have a very specific pollinator. To attract the pollinator, they produce complex sex pheromones that mimic the scent of a female ready to mate. The pheromones as well as the orchids appearance tricks males into mating with the flower. It is a sophisticated form of trickery. This is a form commensalism whereby the orchid species benefits and the insect is unaffected.

Its amazing to think of the evolutionary adaptations that have taken place. Only the best smelling and nicest looking flowers have been favoured by pollinators thorough the evolutionary history of the species, resulting in the highly unique form and function we see today.

I know there is some people on this site who are actively into mycology and native plant propagation, which is great, because these people will have the skills and equipment necessary to propagate native terrestrial orchids from seed. There are still many orchids that are threatened with extinction that nobody knows how to successfully cultivate.

Many species are relatively easy to propagate, as they can be grown asymbioticly (without the presence of the symbiotic fungi). Whats needed is a culture medium (I recommend the W3 medium from Western Orchid Laboratory). Make the medium by simply mixing with water, pouring into jars and sterilising the jars. Mix the seeds with household bleach for 8 minutes, pour the seeds/bleach onto filter paper, wash off bleach with distilled water, scrape off the seeds with a bent piece of wire and spread evenly over the growth medium. Close the jar and wrap parafilm or gladwrap around lid. People with experience in mycology will know how to do this without getting the medium contaminated. Keep jars indoors in a cupboard for ~2months until they have sprouted and are ~2mm in hight. Place them in a position which receives indirect sunlight (Southern window-sill is perfect). After a while it will look like a bed of grass with potentially hundreds of seedlings. When they start getting crammed in the jar, reflask them by picking them out with tweezers into a larger jar with the same growing medium. Eventually they will have developed large tubers and can be moved into formulated potting mix.

The harder ones require the growth medium to be inoculated with fungi. This is done on a petri dish by spreading the seeds over the growth medium and putting a piece of fungi on the edge. The fungi will spread as the seeds germinate. This is a lot of work, and beyond the scope of most plant enthusiasts. The good news is that there are many knowledgeable people in groups such as the Australian Native Orchid Society (ANOS) that are more then happy to help. They most likely will already know and have on hand the fungi species and culture medium that is needed. Just remember that other species of fungi often work just as well and often better than the one found with the orchid in the wild.

If anyone is interested and wants more info on what to do, let me know and I'll help you out.

I just need to point out that taking orchids from the wild is illegal for a reason. It disturbs the soil and potentially destroys the fungal balance underground, and leaves the site vulnerable for weed invasion. Plants from the wild live in conditions different to those in cultivation, and will most likely not survive.

Since getting into native terresterial orchids, I've been out and about photographing them in the bush. Below is a compilation of photos I took in 2012 of orchids in Anglesea

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From Left to Right, top down

1 - Purple Beard-orchid - Calochilus robertsonii

2 - Small Spider Orchid - Arachnorchis parva

3 - Bristly Helmet Orchid - Corybas hispidus

4 - Large White Spider Orchid - Caladenia venusta

5 - Large Bearded Greenhood - Pterostylis sp. aff. plumosa

6 - Great Sun Orchid - Thelymitra aristata

7 - Gnat orchid - Cyrtostylis reniformis

Here is some orchids I have flowering in the greenhouse at the moment

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Edited by juzzoa
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That Helmet Orchid is a beautiful flower and is showing up in a lot of other places around our area, though due to the climate where they are are only sending up the flower stem now as opposed to the ones in the photo which we took nearly a month ago. And you are right we have had an absolute bumper year this year for rain, coupled with a burn off in this particular park which cleared a lot of the bush leaf litter

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Who's MORG?

Nice find on the Corybas, Horizon. Love these little dank forest floor denizens.

All of those three you posted images of are ostensibly pollinated by fungus gnats. The basis of pollinator attraction is still not understood though. I think there are probably exciting tales of mimicry and evolution in fungus gnat pollination, but the biology of gnats and their role in ecosystems is still poorly known.

I don't know if you know this, but the labellum of Pterostylis nutans retracts at touch. Underneath the "hood" you'll see the curved "tongue". If you take a thin stick and touch it to the tongue it will spring quickly up. When done to a gnat this forces the insect against the reproductive parts of the plant as it exits the flower.

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^^ So much chemical, physiological and evolutionary research needed on the pollination systems of our terrestrial orchids.

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