I grow mugwort and alecost to use for making gruit. Mugwort gives a mild bitterness and has a sort of generic herbal flavor. Alecost (aka Costmary) has a really distinct aroma that’s difficult to describe, maybe floral, minty and cinnamon? but not quite. It can also be quite bitter (at least when chewing it) so I’ve been a little gun shy on using it for a long time in the boil, but at FO/whirlpool it’s quite nice.