I'm glad there are botanists around. I only think of them as red flowers, or yellow flowers ... These look like they are made of crepe paper. they are beautiful, I agree.
Just wave your hands, and act like you know what you are talking about. Something like, "I read in a nature magazine about a sort of green plant, that is a cousin to the cactus, but has blue-green flowers. The name escapes me at the moment, but it grows to be about this big (it doesn't matter how big your hands are spread aprt) ..." They'll do the 20 question dance everytime. :)