1st -
You can always take 10 on checks to extract materials from plants or animals, and you do not risk poisoning yourself. You know the DC of any special attacks of any creature you are able to identify.
4th -
When using extracted materials, your crafting time is halved. You can always take 10 on Craft: Alchemy checks, even while under duress.
7th -
When using a poison or material you collected, you can add your Tier to the DC to resist the effects of the item, whichever is higher.
10th -
You are immune to poison, and you can cast Commune with Nature 2/day.
You can apply refined poisons to a weapon or piece of ammunition as a move action with no chance of failure. If an ally is poisoned, and you have the same poison in your possession, as a full-round action you can apply reagents to convert your poison into an anti-venom; once applied any damage the ally has taken remains, but they no longer have to make checks to resist the poison.