I have a short list here where I drew up a few herbs with brief descriptions and areas of use. I never actually finished the list, and also never made use of it for anything because I dropped the project in which I had planned to make use of them. The intention back then was to use them in a low-magic setting, where herbalism and alchemcy would displace the more profound effects of actual spellcraft, and be much more accepted by the superstitious locals - similar to Ravenloft. Because of the locals' superstition I wanted to portray these herbs more along the lines of a fictional natural medicine, rather than something that would actually create magical effects through semi-supernatural means.
I figured I could post them here though and you could grab what you want - if anything.
Black moss
These dark, dry mosses grow almost exclusively on fallen trees, or around the trunk of dead and dying trees. It is not a moss per definition but rather a type of lichen that parasitically drains the tree of its vital nutrients and water. Black moss, ground into fine powder and moistened, makes a thick, starchy paste that when placed upon, for example a snake bite, can absorb the poison and prevent it from causing harm.
Blood Weed
Found around inland lakes and along brooks and creeks, these blood-red, razor-sharp growths can cause many unintended lacerations. The cuts caused by trampling into a patch of blood weed may only be shallow, but an anticoagulant within the plant, similar to that of mosquitoes and leeches, will also ensure that the bleeding will be profusive and enduring.
Blood weed is only rarely used for medical purposes, but it has seen much use by nefarious individuals. The poison can be applied directly to the blade of a weapon, simply by carefully stroking the Bloodweed against the edge and pressing out the poison unto it.
Red Root
While actually possessing a dull greyish colour, red root derives its name from the colour of the soil where it is usually found. Red root grows in soil rich with minerals such as copper and iron, causing the ground to be reddish in colour. It grows just below the plant litter where a keen eye can sometimes spot the root immediately after brushing leafs and twigs away.
If chewed, red root is a powerful hallucinogen and may cause nausea, disorientation and general confusion. However, when only a small amount of red root distillate is mixed with a fluid and ingested, this effect is much less pronounced, instead providing the consumer with a sense of well being and calm, relieving anxiety and sometimes even panic.
Widow’s Wort
Black like a widow’s dress, these herbs are fragile and need very specific environments in order to grow and thrive. They need almost perpetual shade to shield it from the burning rays of sunlight and they enjoy humid environments. Because of that it is rarely they are found in any areas but underground, in caverns, or under the thick canopy of elder forests.
After brewed in boiling water, Widow’s Wort makes a bitter, foul tasting tea that is known to quickly make consumer alert and wide awake as well as relieving him from muscle fatigue. Although similar to effects of a short nap, repeated consumption should not be considered an alternative for a good night’s sleep – as it may cause damage to internal organs.