This very fragrant shrub was growing in a planting of about six on a private property near Haena on Kauai. It looks like something I might see in Vancouver, but I've never noticed anything with such strange flowers - very tiny flowers backed by what I'm guessing are three bracts that grow next to each other on one side of the flower. Not all of the flowers had these extra bits. Narrow leaves were maybe around 10cm long. A few of the bushes had darker green leaves that were grey on the back, and those flowers were a slightly different colour of white.
Looks like Euphorbia leucocephala. https://www.google.co.uk/search?q=E...g&biw=1920&bih=967&sei=cALDUPPUF4em0AX2t4GgAw http://www.google.co.uk/imgres?um=1...28&start=33&ndsp=41&ved=1t:429,r:35,s:0,i:194
Thanks, Silver surfer. It certainly does look like that. It has a ton of common names - Little Christmas Flower, Pasquita, Snow Flake, Snows of Kilimanjaro, Flor de Nino, White Small Leaf Poincettia, Snow Bush, White-laced euphorbia. From Central America. I did check to see if it might be a type of Poinsettia (it's a relative), but I didn't come across it.