Absinthe Botanicals - What part of the plant to use

[Redwave11]

Hi All,

TLDR: Does anyone have any insight into macerating fennel in it's non-seed form and the effect this has on the final product?

I have noticed that some recipes are rather general and others are very specific when indicating which part of each botanical to use. Eg. Grand Wormwood vs The flowering tips of grand wormwood.

In particular I was interested with the use of fennel seeds vs stalks vs crown vs foliage. Most modern recipes seem to say seed however the old texts simply say fennel. A couple of contributors use the fennel crowns in their recipes and say it imparts a more round flavour, but more broadly there isn't much discussion.