What is Nicotiana?
Nicotiana refers to a genus of herbs and shrubs of the nightshade family (Solanaceae) indigenous to North and South America, Australia, south west Africa and the South Pacific. Various Nicotiana species, commonly referred to as tobacco plants, are cultivated and grown to produce tobacco. Of all Nicotiana species, Cultivated Tobacco (N. tabacum) is the most widely planted and is grown worldwide for production of tobacco leaf for cigarettes. The genus is named in honor of Jean Nicot, who in 1561 was the first to present tobacco to the French royal court.

Many plants contain nicotine, a powerful neurotoxin that is particularly harmful to insects. However, tobaccos contain a higher concentration of nicotine than most other plants. Tobacco leaves and sometimes stems are commonly used as entheogens and for pleasure. The leaves are processed into forms that can be smoked, chewed, or sniffed.

In many industrialized countries, nicotine is among the most significant addictive substances and a cause for medical concern; see Health effects of tobacco smoking and Smokeless tobacco#Health issues for details. By contrast, in preindustrial societies, tobacco smoking was almost invariably considered a sacred or ritual activity and tightly regulated. Smoking a Native American "peace pipe" would invariably be preceded by paying due homage to the relevant deities and spirits and sacrificing some of the tobacco. Other cultures such as the Aztecs, while smoking tobacco more casually, were nonetheless aware of the fact that it is a potent and addictive drug. See also Religious views on smoking. Native peoples also used tobacco in other ways as an entheogen (e.g. as an additive to ayahuasca), and occasionally in ethnoveterinary medicine, e.g. to rid livestock of parasites.