The Circle of Spores Druid gets the level 2 feature Symbiotic Entity, which does the following:
As an action, you can expend a use of your Wild Shape feature to awaken those spores, rather than transforming into a beast form, and you gain 4 temporary hit points for each level you have in this class. While this feature is active, you gain the following benefits:
- When you deal your Halo of Spores damage, roll the damage die a second time and add it to the total.
- Your melee weapon attacks deal an extra 1d6 necrotic damage to any target they hit. These benefits last for 10 minutes, until you lose all these temporary hit points, or until you use your Wild Shape again.
These benefits last for 10 minutes, until you lose all these temporary hit points, or until you use your Wild Shape again.
It's not clear to me if the temporary hit points are included in the benefits that expires after 10 minutes, or if the temporary hit points can last until a long rest like usual.