It is (almost certainly) a hybrid of the so-called Dendrobium phalaenopsis type. That doesn't mean it is a phallie, of course , just has flowers which resemble many phallies - whereas most of the other types of dendrobiums are quite different. Dendrobium phalaenopsis itself - that particular species which is the backbone of breeding in this area - is also known as D.bigibbum.

I find them needful of a lot of water when in growth, and moderate amounts at all times, so your tree might be a bit dry for them. Why don't you hedge your bets - put a couple on your tree, and grow the others differently ? I have even had them in a glass of water for a week in a hotel bedroom, to keep them plump before returning homer and potting up, and found they liked that !