How to build.
Once you have created your Druid city, enter the Field and click on one of the three field plots, then click on Druid Apothecary; click Build, and you're building your first Druid Apothecary!
This version of the Apothecary lets you revive not just your troops from before you ascended your city, but also the new Bloodthorn Unit. Also, you can get a minor blessing once you ascend your Druid city to level 2 that lets you have not one, but two revive queues. That means two troop types reviving at the same time!