Ok, it wasn't Herb Alpert found in the woods... but a little tiny plant that seems to have mystical properties of healing, that if worked properly can actually save a life. cure an illness. heal an injury. or if the right one found... kill you.
In my campaign world, I have augmented the notion that there is little to no good clerics in the world. Since it's run by Hextor, healers really are not something commonplace. So that's where herbs come in play.
I have a list, which you can find here.
This list shows you that you can find all sorts of different herbs. the chance of finding them, and the dosage of each herb, depending on the roll you make, and the skill level you have.
DM rolls on Table 1 and/or table 2. he adds in the characters herbalism skill (knowledge and profession) to adjust the number rolled up. Knowledge skill counts as 1 per rank. Profession is doubled. so, if he has 5 ranks in knowledge, it's +5 to the die roll. If he's got 8 ranks in profession herbalist, then he gets +16 to the roll. Playes choice on if he wants Plus or minus.
Once he gets a level of herb, he then rolls the D for # of the herb potentially found. For every 5 ranks in either skill, the DM can adjust this roll up or down 1.
Then the player rolls his search DC. Herbalism profession or knowledge needed, and synergy from search to provide an extra +2. If the character has both profession and knowledge herbalism with at least 5 ranks in each, he gets a +2 to this roll.
Once found, the player needs to rest and create the items. Specific times are also listed for how long it takes to make them.
Once the player creates the item, he rolls his create DC (synergy with alchemy and healing impart a +2 synergy each for every 5 levels of those skills.
If a failure, then all is wasted. If he succeeds, the DM rolls how many doses he created. If the character has both profession and knowledge herbalism with at least 5 ranks in each, he gets a +2 to this roll.
If each is at least 10 ranks, then he gets a +2 to the max dosage.
IE: dosage is 1d4 normally. With 5 ranks of each, he gets a +2 to the roll, with a max of 4 possible. With 10 ranks, he gets +2 to the roll of 1d4+2, so he can possibly get 6 dosages.
I know this seems rather convoluted, but it does seem to work. I suppose you could always just go with the random, DM's choice award and just pick yourself which one he gets and how much.