And they’re part of a plant family, Annonaceae, that is mostly tropical, so they’re one of the only — they are in fact the only genus in the family that grows this far north.

它们属于植物科番荔枝科， 主要分布在热带地区，因此它们是仅有的一种——事实上， 它们是该科中唯一生长在如此遥远北方的属。