Bloodthistle

Bloodthistle is a herb native to Eversong Woods. It grows in and around areas of blood elf magical activity (i.e. near buildings). It can only be used by blood elves to get a +10 to their spell power. No other races are able to consume the herb. After the buff fades, the consumer of the Bloodthistle will be afflicted with Bloodthistle Withdrawal for 20 minutes, which reduces Spirit by 5 from the lack of Bloodthistle. The buff stacks with all other buffs. The debuff can be cured by consuming more Bloodthistle (which delays the withdrawal), casting a mage's Ice Block, or activating a paladin's Divine Shield.

A frequent consumer of bloodthistle is called a "thistlehead", and looked down upon by common blood elf society. Selling bloodthistle seems also to have been outlawed in several places, such as Shattrath City. According to the Illidari blood elves, Eclipse Point is full of thistleheads.

Due to the fact that Bloodthistle is not currently used in any trade skill recipes, a budding herbalist can find Bloodthistle to be a good source of early income compared to other herbs of its level (Peacebloom and Silverleaf only sell for a piece) because it is found in great quantities in the Eversong Woods and sells for  a piece ( for a full bundle of 20).