Thats a schefflera. The white powder could be mildew or more likely if like white cotton then is probably mealy bugs. You can use rubbing alcohol with q-tips. You have to be persistent to get rid of them. Isolate the infected plants from the non-infected ones.

Okay, first off, I don't know anything about plants. Clearly. My boyfriend's mom gave him bamboo a couple of years ago and now I have half of it while he's in Iraq. I had placed my houseplants outside once the weather got warmer outside here in DC and 2 days ago, I put the bamboo outside. It has grown at least 6 inches since I've had it (about 9 months) and I have it in a lot of water in a very tall glass vase. My problem is that last night when I came home, the bamboo was fine....but now it's turning white. Not yellow....totally white. I took it out and washed it in filtered water, removed some of the leaves, and put it in a clean vase with fresh water. Is there anything else I can do? Thanks!!!

maybe a type of scale. see photos at the link below. these pests can be controlled with applications of horticultural oil. Here is a link that might be useful: pulvinaria

Judy, the foam protects them from any chemical you might use. If your hydrangea is the size you describe, you can spray away the foam with water, or take a paper towel, wipe them off and squash. You're going to find a little green to yellow-green soft nymph inside the foam. The nymph is sucking sap, causing the distortion. And when you're done with your hydrangea, you can come and do my lavender - they are covered this year, along with the hardy fuchsias :)