We have a rather sticky-ly thorny bush here that grows in patches on my homestead place. I've known it as thimbleberry since moving here. Just recently I had a mainland visitor who informed me that the leaf was quite different from the thimbleberry he was familiar with, so I had to go look it up. And he was right! Turns out that his homeland thimbleberry is a kissin' cousin to mine. His has the scientific name Rufus parviflorus while mine is Rufus rosifolius. The leaf shape is the most apparent difference I first noticed. The Hawaiian thimbleberry leaf looks more like a rose bush.
Right now the thimbleberries are flowering and creating little red berries the size of raspberries. When ripe, they are red. It's easy to know when they are ripe because they readily come right off the bush and look like little red thimbles. While edible, I find there taste to be insipid. (Hey, how often do you get to use that word!) In plainer words, they're flavorless. But if I wanted, I could surely eat them. The fruit production is sparse, so it would take a massive area of thimbleberry to produce enough fruit to make a cup of jam. But a small handful is do-able and would make a nice decorative statement in salad or atop a cake.
My rabbits like to eat thimbleberry. They'll eat the entire bush except for the thickest stems, and those they will debark. So I allow thimbleberry to grow so as the be part of my rabbits' diet.
I find thimbleberry to be an annoyance.......except for the rabbit forage part. It's very thorny. It creates a tangle. It spreads readily via underground shoots. It is difficult to remove by hand and grows back if you leave roots behind.
For rabbit forage I allow it to grow about 2-3 foot high then snip it off at ground level, using a hand pruning shears and then cut it into 12-18 inch long lengths.