Burdock & Velcro
Burdock, the more obscure of the ingredients that comprise the traditional English drink Dandelion & Burdock, was the inspiration behind Velcro.
In 1941, Swiss inventor George de Mestral wondered why burdock seeds stuck so easily to his dogs fur, put some under a microscope, and copied the hook-and-loop system to stick other things together.
It took him 15 years to refine the system and get his first patent. The big breakthrough came when he made the hooks a lot smaller and more numerous than the loops; this way, hook-ups are guaranteed when the two touch.