Dipodium variegatum

[kitkor]

Hello, all! As part of my academic work on the genus Dipodium, I recently traveled to Australia in January and February 2014 to collect specimens (all with valid permits, of course).

I think one of the most stunning species I encountered was the blotched hyacinth orchid, Dipodium variegatum. The species in this genus are tolerant of hot and dry conditions, so they're often the only orchids flowering in the summer. They are mycoheterotrophs with leaves reduced to scales around the base of the stem, held usually just below the soil's surface. Cultivation is impossible without the fungal partners and host trees the fungi inhabit. Anyway, I think they're quite pretty.

In the Pridgeon et al. classification of orchids (Genera Orchidacearum), this genus is allied with Cymbidium, Grammatophyllum and others in the subtribe Cymbidiinae.



Dipodium variegatum, Meroo National Park by Kitkor, on Flickr

I have almost finished uploading photos from my trip to this flickr album, where you'll find more photos of Dipodium.

[orchidsarefun]

wonderful photos, thanks for sharing. That's an interesting orchid with probably little hope of surviving outside of its habitat.
That pie shop sign brought back gastronomic memories of Aussie pies. Not as good as South African pies, but in that ballpark. Its taken us 10 years to find similar pies in the USA......

[WhiteRabbit]

Beautiful!

[kitkor]

Thanks! Yes, the mycoheterotrophic species don't survive very long after being transplanted. The folks I talked to at the National Herbarium of Victoria in Melbourne (at the botanical gardens) told me their staff had successfully moved one with a large clump of soil. The plant flowered for two years after it was moved but failed thereafter perhaps after using up the reserves in its fleshy roots.

I'd have to say that the Aussie pies weren't my favorite item from the trip. I did, however, enjoy the constant presence of tea and the importance of "tea making facilities" advertised for all the motel rooms I stayed in.

[King_of_orchid_growing:)]

I commend the people at the National Herbarium of Victoria, for transplanting this species of orchid, but I believe that conservation of orchids like these are best done with seed propagation.

Vegetative propagation of terrestrial orchids that grow tuberoids is possible, but they're generally very prone to dying off when growing conditions are not favorable in any way, and they reproduce at a slower rate. I'm on the boat of, if they are successfully reproduced by the hundreds using seed propagation, they stand a far better chance of survival.

At the moment, I believe that one of the few species of Dipodium that people are able to successfully grow in cultivation is Dipodium pandanum. If there are any other species of Dipodium that grow similarly to Dipodium pandanum, those are the ones that are going to be amenable to culture.

[kitkor]

Philip,

Indeed. I don't believe the folks at the herbarium in Melbourne had grand ideas of extensive conservation. My impression was that it was a simple trial to see how sensitive the mycoheterotrophic species were. They expressed surprise that it flowered for two years after the move. Their short experiment emphasizes the importance of in situ conservation for these taxa.

Yes, the other species of Dipodium are cultivatable but are rare in collections. Dipodium ensifolium from Queensland is probably the easiest as it is terrestrial. All the other leafy Dipodium are climbers and are a bit harder to cultivate. Dipodium paludosum and D. pictum are occasionally found in cultivation.

Cheers,
Ryan

[ChipMolly]

Amazing flickr photos thanks for sharing! I am curious, why Australian natives? In NSW did you see many of these species?

http://plantnet.rbgsyd.nsw.gov.au/cg...h=orchid&dist=

I'm going to start visiting the creeks and reserves around North Sydney myself in the coming year to look for species in situ.


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[kitkor]

Hi, ChipMolly,

Why Australian natives? Well, I'm looking into the degradation of the chloroplast genome when a lineage transitions from leafy to leafless. This shift is associated with transitions from a climbing or epiphytic habit to a terrestrial one, which has an impact on the fungal endophytes with which the species associate. There are lots of interesting questions in these kinds of orchids and one of the best -- and so far under-investigated -- examples of this occurs in the genus Dipodium. I still need to collect farther north in Queensland and in Malesia so there's plenty of work to do yet!

I was collecting in January and February, so most other orchids were not in flower. The only other genera I saw were Prasophyllum and Thelymitra at Alpine National Park in Victoria. I didn't have time to visit sites that Dipodium wouldn't be at and I'm sure I missed out on some amazing locations for other orchids. Such are the constraints of a research trip!

Cheers,
Ryan

[ChipMolly]

Originally Posted by kitkor

Hi, ChipMolly,

Why Australian natives? Well, I'm looking into the degradation of the chloroplast genome when a lineage transitions from leafy to leafless. This shift is associated with transitions from a climbing or epiphytic habit to a terrestrial one, which has an impact on the fungal endophytes with which the species associate. There are lots of interesting questions in these kinds of orchids and one of the best -- and so far under-investigated -- examples of this occurs in the genus Dipodium. I still need to collect farther north in Queensland and in Malesia so there's plenty of work to do yet!

I was collecting in January and February, so most other orchids were not in flower. The only other genera I saw were Prasophyllum and Thelymitra at Alpine National Park in Victoria. I didn't have time to visit sites that Dipodium wouldn't be at and I'm sure I missed out on some amazing locations for other orchids. Such are the constraints of a research trip!

Cheers,
Ryan

Can you recommend some recent journal literature articles?

[RosieC]

Really lovely!