Sweet tangelo is the sidekick in this tart-and-tangy shrub flavored with rosemary.
'rosemary' on Serious Eats
Ripe, almost squishy peaches work great for this cocktail, since the peaches will be muddled anyway and you're looking to get as much peach juice as possible.
This cocktail is, for all intents and purposes, a greyhound, but I make it with fresh-squeezed pink grapefruit juice (Rio Star from Texas, if you're into cowboys) and rosemary simple syrup. It's a real dandy.