Khat (Catha edulis, family Celastraceae; pronounced /ˈkɑːt/; Arabic: قات; Ge’ez č̣āt; Somali: qaat), also known as qat, qaat, quat, gat, jaad, chat, chad, chaad and miraa, is a flowering plant native to tropical East Africa and the Arabian Peninsula.
Khat contains the alkaloid called cathinone, an amphetamine-like stimulant which is said to cause excitement, loss of appetite and euphoria. In 1980 the World Health Organization classified khat as a drug of abuse that can produce mild to moderate psychological dependence. The plant has been targeted by anti-drug organizations like the DEA. It is a controlled/illegal substance in many countries.
For centuries, khat, the fresh young leaves of the Catha edulis shrub, have been consumed where the plant is cultivated, primarily in East Africa and the Arabian peninsula. There, chewing khat predates the use of coffee and is used in a similar social context. Khat has been brought into the United States and other countries for use by emigrants from the source countries. It contains a number of chemicals among which are two controlled substances, cathinone and cathine. As the leaves mature or dry, cathinone is converted to cathine, which significantly reduces its stimulatory properties.
Methcathinone, commonly called cat, is occasionally confused with khat. Methcathinone is a synthetic Schedule I substance that has a similar chemical structure to the cathinone in the khat plant. Methcathinone is produced in clandestine laboratories and sold as a methamphetamine alternative. The addictive properties and side effects of this synthetic are more intense than either of the naturally occurring khat substances.

Tobacco is an annual or bi-annual growing 1-3 meters tall with large sticky leaves that contain nicotine. Native to the Americas, tobacco has a long history of use as a shamanic inebriant and stimulant. It is extremely popular and well-known for its addictive potential.
Nicotiana rustica leaves.
Nicotiana rustica leaves have a nicotine content as high as 9%, whereas Nicotiana tabacum (common tobacco) leaves contain about 1 to 3%
A cigar is a tightly rolled bundle of dried and fermented tobacco which is ignited so that its smoke may be drawn into the mouth. Cigar tobacco is grown in significant quantities in Brazil, Cameroon, Cuba, Dominican Republic, Honduras, Indonesia, Mexico, Nicaragua, Sumatra, Philippines, and the Eastern United States.
Tobacco is an agricultural product processed from the fresh leaves of plants in the genus Nicotiana. It can be consumed, used as an organic pesticide, and in the form of nicotine tartrate it is used in some medicines. In consumption it may be in the form of cigarettes smoking, snuffing, chewing, dipping tobacco, or snus.