are the bumps are on the plant or part of the plant? If it is on the plant,it is hard body scales. If it's part of plant,it might be internally . I wish could see the damage.

sounds like mite damage to me. Down here bougainvilleas are often infested with mites and the leaves get bumpy and curly and the bracts small and twisted a bit. A mitecide will take care of the problem....chris

Thanks, Chris! I think the mites are the problem. Finding an effective miticide that's not illegal is a slight problem here in the USA.

Sorry, ton2menehune, I've only recently joined the 21st century, and I'm still fumbling with my digital camera and the procedures for including images in my posts. Hope to figure it out soon, but in the meantime, I'm fumbling with verbal descriptions. The actual tissue of the leaf is arched upward between the veins, causing a pebbled texture to the upper side of the leaf, like some reptile skins. The critters allegedly responsible aren't easily visible to the naked eye, and if they are like some mites I know, they do their damage inside the leaf buds. I'll do some research re mites on bougies, and hopefully confirm or deny.

The man who stares at leaves,
Kevin : )