AusBonsai

How are others' doing? Any flowers yet?

I took this photo of my Pterostylis hispidula the other day.

Mine are up but no flowers as yet.

No autumn flowering species here either Joel. Leaves are up on P. nutans, P.curta and another unknown Pterostylis species that has refused to flower. I suspect it may be an autumn flowering one but might need smoke to trigger flowering. I'll try to remember to give that a go next summer.

Leaves of Diuris have just emerged this week. that there will be some seedlings in this one after leaving some seed in the pot last summer.

Cheers guys. I have P. alveata, laxa and the hispidula above in flower, with the hybrid conoglossa not far behind.

Shibui, have you tried the banana peel trick with the genus Pterostylis? I know that Les Nesbitt claims to not have seen Leptoceras menzeisii flower in cultivation without it. Not sure how transferable this stimulus is across genera though.

Good luck with the seeds! I've had no luck with any orchid seed yet. Still hoping for my Spiranthes though.

I have used banana peel in the past. Smoking does the same thing but quicker.

Something a little different: Corunastylis fimbriata. Notice the small vinegar fly with two pollinia on the head.

It is not known if this species is amenable to long term cultivation. It is likely dependant on fungi to survive.

These plants are being used for genetic research.

Pot by 42 Mice.

Very pretty plants!

How have you found growing / propagating them?

Wow mother nature and all the contributors in this post.

Joel, stunning photo of the pollinator. I am curious what you mean by genetic research, from the technical what & how thru to what you hope to learn from it?
JJ

Jow wrote: How have you found growing / propagating them?

Jow, I'm not sure if I am actually growing them at this point or just sustaining them on their reserves. They store photosynthates from previous seasons in tubers below the soil and it is suspected to be obligate to fungus to survive. If the culture isn't correct, the fungus won't survive and it will continue to grow and flower as normal until the reserves in the tubers are used up.

These were donated to me in the pots they are in. It appears as though the pots contain mostly site soil and a little bonsai mix around the edges. Site soil has a clay base with a shallow loam layer above on which a thin organic layer and leaf litter sits. It is believed that in general the fungi that are in relationships with most of our tuberous orchids tend to only occupy the top layer of organic matter.

I want to ensure the plants are available for future studies if required, so the few remaining plants I will pot on. Obviously the clay content in the site soil will soon prevent proper drainage so I will repot next dormancy. As I mentioned above, the fungal species is presumed to occupy only the top layer of organic matter. I want to try and replicate the site soil as much as possible without sacrificing drainage.

I have elected to use kanuma as the base layer. It will not host other saprophytic fungi which may compete with the beneficial species, as it is not organic. Further more, it has similar properties as the clay subsoil; similar CEC, similar pH and WHC. Replicating the site soil as much possible will be essential to survival of the fungus and therefore plant.

On top of the kanuma I will add a small quantity of site soil with clay subsoil. Not enough to completely impede drainage when it inevitably washes through the kanuma, but enough to inoculate the kanuma with similar microflora to what has persisted in the pot it is in now (and hopefully the original site).

Above that I will place the dormant tubers before covering them with the upper layer of soil from existing pot and a thin layer of leaf litter. I will use the leaves of Eucalyptus umbra, Leptospermum polygalifolium and Poa sieberiana as they were present at the original site.

Despite this planning, I am not terribly confident they will survive long term. As I said, my goal is to allow them to persist long enough for research purposes. Developing a stratergy for long term ex-situ survival would be an excellent bonus though as many species are threatened.

As for propagation, it looks as though the vinegar fly did a fine job of pollinating them and pods are starting to develop. As I have allassosciated data, I will attempt to donate these to a seed bank. In the event they are rejected, I will attempt to germinate them myself. I have even lower hopes for this as the seeds too require a specific fungus for germination to occur. Basically the idea is to isolate that fungus in a Petri dish and attempt to sterilise the seeds before adding them to the fungal culture. It is unlikely that the species utilised for long term survival is the same as the species required for germination so isolating the correct species (and it's probably not described) will be very hit and miss.

However, if long term cultivation is successfu, the plants should slowly grow more tubers stacked on top of eachother. Unlike some other species of terrestrial orchids, these do not naturally sever to form new plants as instead they are used to help the individual plant survive in poor years. But by separating the stacked tubers during a repot, one could likely encourage new growths from each that is separated but at the cost of it's resilience in non ideal cultivation.

If you can't find experienced terrestrial orchid growers around Sydney you should seek help from ANOS Vic or SA. There seems to be far more growers down here. Botanic Gardens in Vic have been doing a lot of work on conserving orchid species. I have been peripherally involved collecting seed for storage and germination and tissue samples to extract fungi. As far as I'm aware the same fungi in the plant is used for germination purposes. They have a program of germinating endangered species and returning plants to the bush however funding limits the number and species they can propagate.
For cultivation we found that using site soil in pots inevitably leads to tubers rotting when dormant. Very free draining mix, very like modern bonsai mix, is best with good organic levels (buzzer chips) which provide food for the fungi. I'm currently using bonsai mix to grow the few species I now cultivate - all easy to grow species though.

Fungi are present on and in the tubers and plant stems and should transfer to the new mix when plants are potted up - provided conditions are correct for it to survive. I don't believe there is a need to transfer site soil to the new pots. Fungi already on the plants should be enough to start colonisation.

jumping_jack wrote: I am curious what you mean by genetic research, from the technical what & how thru to what you hope to learn from it?
JJ

Hi JJ,

Sorry it has taken me so long to get back to you. Great question!

First off I should say that I'm not conducting the research myself. I work in evolutionary ecology, not botany or taxonomy.

I believe the samples I sent off will be used to test taxonomy. DNA is extracted then sequenced. From there, you can compare the relatedness between plants. Botanists have previously used morphology (the shape of the plants, particularly the flowers) to infer relationships between these orchids. Some work has been done genetically but this was a few years ago when it was hugely expensive so only a small amount of data were produced. I think the aim of this is to test whether those findings still hold and provide more robust data if they do.

I've not worked in taxonomy so take what I said with a pinch of salt. I'm happy to contact the researcher if you'd like more details.

Just a reminder that If you haven't repotted your tuber forming terrestrial orchids and intend to this season, DO THEM NOW.

I repotted all mine last week.
Just planted the spare tubers into the 'indigenous' area this afternoon as they are all local species.