The problem with common names is confusion. This tree has nothing to do with orchids. Lots of information in the link. My common name for it is butterfly bush. Sorry, no idea how to grow it except it is probably not frost hardy.

Here is a link that might be useful: Hong Kong Orchid Tree

As Arthur said, not an orchid or even related.

I had a couple big Hong Kong orchid trees back during the years I lived in S. Florida. They were planted all over Miami through the 1900s. No problems with them, no special care, plant and water and they grow into big trees. Frost doesn't bother them since they are usually dormant and leafless during the coldest months.

Unlike other Bauhinia species, the Hong Kong variety is sterile so you don't have seedlings popping up all over your yard.

They grow like weeds for me. I have to use round-up to keep them under control; but then I have the white variety. I should get one of the pinks; I'm told the colored hybrids don't produce viable seed. I wonder if they've possibly hybridized the horrible thorns out of the plants.

They do bloom profusely.

I have one growing in my solarium. It is about 8 feet tall I have it in a big pot. I drag it outside in the summer then about October bring it back inside. In Washington state the winters are not that cold only about 35 to 40. But when you live in the rain forest you have to worry about rot. I have left cymbidiums out side in winter and they always rot out. I was talking to my wife today and I was mentioning I was going to move it on the deck this weekend.

I had several until this winter in Houston. The big freeze killed them all! In Brazil they are called "Cows Foot Tree". -;))