In order to deter predators the buds produce a blob of sticky goo, hence the name gumweed. Apparently this was used as a skin ointment, amongst other things, by the coastal natives of California, the plant's natural home.
Bizarrely Whitby's west cliff is the only place in the United Kingdom where the coastal gum plant grows. It can be found very easily on the cliffs right in the busiest parts of the town. Up the Khyber Pass for instance, there are plenty of plants just at the bottom of the steps up to the whalebone arch.
This time of year (July) is a good time to look for Grindelia as the buds are particularly nice and gummy. It has increased greatly since first being recorded here in 1977.