its extracted from pretty much anything you can extract it from grass
In some states like Maine 18 is the legal age.
I personally would recommend smoking it NO YOUNGER than age 15, or 16 if the person is a little immature, it is a powerful, introspective experience where you lose all control of everything and get pulled through the experience, it should not be used unless you are completely ready for that. Some people are never ready for that, and thusly, they shouldn't use salvia.
Absolutely, if you are anti-drug and dissagree then is Heroin a better choice?
Acid is non-addictive and helps you see the world for what it truly is. This is something you cannot explain unless you are tripping on it. It is recommended that for any first timers you do in the safety of your home so you can understand the effects.
Salvia divinorum is not currently known to be detectable in hair tests, but tests for it may eventually be created (especially is Salvia becomes a nationally scheduled substance).
no. dmt is metabolized very quickly, and drug tests don't look for it, as it is produced by the human body.
There are different types of salvia plants, some are well-known herbs and spices used in cooking, and some have medicinal properties e.g. different types of sage plants. They are also grown for their attractive flowers as a feature in a garden.
Although salvias in general are not known for being deadly toxic, one salvia species (i.e. salvia dininorum) contains powerful substance, known as Salvinorin A, which has hallucinogenic effects on the human brain. Salvia Divinorum has never been linked to any deaths, so the short answer is, "No."
An illegal hallucinogen made from a specific type of mushroom?
There are many mushrooms which contain psilocybin (along with psilocin, baeocystin and others) that are illegal. The majority of the time the psilocybin is not extracted (although it can be) but rather the whole mushroom is eaten.