there is no answer for that they just spawn randomly
One day i found 27 gold flowers through all 19 channels at orbis cloud parks
the next day omega sector
another day orbis tower
another day at that one edelstein map with the big boulders or something
I find them more often at certain places, Kerning Mall, Amoria, the target dummy area in Mu Lung, the maps before you get inside the clocktower in ludi, the map Bamboo Scroll Warrior spawns on in Herb Town for example. But yes they can technically be on any map with herbs/veins.