Herbalism invites as much creativity as alchemy or engineering, practically begging roleplayers to talk with their companions about all kinds of background knowledge behind each herb, such as how each one came to be called by its current name, as well as its special properties. Feel free to just make stuff up here, and never worry whether or not what you say is accurate. Even with all manner of herbs in real life, there are countless tales about the origins of their names, as well as diverse claims as to their effectiveness in one use after another.
Lichbloom, you might say, is a taint of the Lich King's undead energy, infesting the very land itself and turning it against all life. Or, you might just as easily argue that the herb is quite natural, without any undead taint whatsoever, and that the name merely comes from its ghostly appearance; before the rise of the undead in Northrend, you might claim, it used to be called "whispervine" on account of its spindly tendrils that remind people of whispers in the night (and in fact, this has an element of truth, as apparently the same herb node model was called whispervine in the Wrath of the Lich King beta). You can make up whatever origin suits your character most -- if you are paranoid about the Lich King's influence, then you should see all manner of Northrend items as associated with him in some way, all portents of doom for Azeroth's peoples -- but if you are instead a wacky inventor of alchemical elixirs, then perhaps all these gloomy names have different meanings entirely.
Uses of herbs can vary widely as well, quite apart from anything having to do with alchemy or inscription. Everyone knows that herbs are used in potions and glyphs, but not everyone knows what happens when you touch an herb to your skin, for example. Creative explorations of extra uses (or superstitions) like this is one of the great tricks of roleplaying in WoW.
To continue with the lichbloom example, your paranoid character might claim that one touch of the stuff on bare flesh spreads the corruption of undeath like a rash, and that the only way to counter it is to spread copious amounts of talandra's rose on the affected area. Your wacky inventor, on the other hand, might profess that the name lichbloom is actually a misnomer, since its real name used to be "richbloom" and it is a well known superstition that anyone who rubs it on his skin is likely to get a large sum of money sometime in the near future ( when asked about the rash the paranoid character talks about, the wacky character could dismiss it as a mere allergy).
Herbalists also receive the special power of "Lifeblood," which can heal over time. How exactly your character does this is up to you, of course, but one possibility is that your favorite herb (or mix of herbs) actually has this healing property inherent in itself when applied on the skin or ingested somehow. Alternately, perhaps all this interaction with herbs gives your character a stronger connection to nature, so that you really can "absorb energy and nutrients from the earth" as the lifeblood tooltip says. Or maybe working with herbs has just made given your body a natural healing factor of some kind, even though your class may have no healing power or "connection to nature" at all.
Some classes (such as Druids) are obvious picks for herbalists, from a roleplaying standpoint, while others (such as Death Knights) don't seem to fit as well. Let's examine, for a moment, just one example of the driving motivation behind a member of each class with the hope of showing the broad diversity of attitudes and ideas which could drive your character to run around the world picking flowers. Feel free to adapt any of these ideas in any way you like, or to get inspired and choose something completely different.
- A death knight might use herbalism as a way to maintain her fragile link with life, by harnessing the life energy in each plant and drawing it into herself.
- A druid could take up a great interest in herbalism, not only as another connection to the power of nature, but as a kind of model for how he should live his own life. He may talk of the peacefulness of peacebloom, the wisdom of mountain silversage, or the passion of gromsblood. This would be particularly ironic if the druid specializes in restoration and can turn himself into a tree whenever he talks about herbs, almost as a reflex he doesn't even notice.
- A hunter might similarly associate herbalism with the power of nature, but her emphasis could be on the more practical uses of herbs as home remedies or cures for illness instead of all that philosophical stuff.
- A mage may view herbs, particularly magical ones, as mysteries in themselves, which can be studied in great scientific detail in order to be turned into potions or glyphs. This would be the equivalent of the scientist in the real world who spends all his working time considering whether or not of gene splicing soybeans could help produce a better kind of biofuel for cars.
- A paladin could look at herbalism as a kind of prayerful meditation. To remove her gauntlets and touch a beautiful herb such as sungrass or dreaming glory, would be to touch a ray of the Light itself. Herbs like lichbloom and nightmare vine, on the other hand, might make her feel the utmost contempt as she rips them out of the ground.
- A priest may also take a religious approach towards herbalism, but in a very different way. A troll voodoo shadowpriest, for instance, might see nightmare vine as just the thing to use to summon the spirit of his dead grandfather for advice.
- A rogue, of course, might see each herb as a potential poison ingredient, and discuss all the terrible (or hallucinatory) things that could happen if you were to ingest the stuff directly before using alchemy to purify it.
- A shaman may see all herbs as expressions of the Azeroth's elemental spirits. Icethorn, for example could be the tears of the spirit of water that lies trapped beneath the ice of Northrend, while Goldclover could be fingertips of the spirit of fire trying in vain to bring spring to that icy land.
- A warlock may see herbs as essential ingredients in his diabolical magical experiments, and may claim that he also gathers other things to fuel his magic as well (such as goat's bladders, tadpole tongues, and fingernails carefully removed from human hands).
- A warrior might just collect herbs as a way of staying sane in the face of all the destruction and carnage she sees going on about her.
Whatever herbalism may mean to your character, it's bound to provide endless opportunities for creativity and imagination, if you just connect the dots between your own character's mindset and the names of the herbs you collect.