Hops come to brewers either as thumb-sized bundles of leaves called cones or flowers (the botanical term is strobilus, and they’re closer to pine cones than actual flowers), or ground up and packed into tiny, rabbit-food-like pellets. The cone-vs.-pellet debate is long and popular.
Lagunitas uses pellets. They have to, because whole cones won’t fit into the air cannon head brewer Jeremy Marshall uses to fire hops at 70 psi into the fermenters. That’s called dry hopping, and Lagunitas dry-hops a lot of their beers. We saw these boxes of hops last time we were up at the brewery. “Sum” is for Summit, a really bitter, grapefruity hop. Fill in the blank for the other one.