Thanks so much for the help - this truly is a friendly and helpful forum.
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I would never have found diplocaulobium without your help. It definitely is, and now I'm trying to check the species against photos on the web.
I was wondering if the second photo was dendrobium gouldii from a picture in Pridgeon's encyclopedia - which would fit with Taipan's identification. We live at around 5100ft here, and I've seen quite a few of these about.
I couldn't get any results from the orchids PNG page - does anyone elsewhere have better luck?
Thanks again,
Phil