I love these stamps btw. Especially the compost one. I wonder if they do anything but advertise being green? Like maybe they could be made of compost, or specially decomposing material (but maybe they couldn’t be forever stamps)? Maybe there’s some incentive for the gov’t to do it! Then again, maybe forever is revokable if the post office gets sold to UPS, Fedex or GE. Or if it just lays off enough workers that the new motto is snow? Rain? Heat? Fuhgeddaboudit.

Milk thistle?