Catnip

Nepeta cataria, catnip or catmint, is a species of the genus "Nepeta". It is in the Lamiaceae family. The name "catmint" is sometimes used for the genus as a whole. Some plants can cause diarrhea to cat's.
Cat behaviour.
Catnip, and some other species in the genus "Nepeta", is known for its effects on cat behaviour. Cats rub on the plant, roll on the ground, paw at it, lick it, and chew it. Some leap about and purr, some cry out. Cats do it for about five to fifteen minutes, after which olfactory fatigue usually sets in. 
The nepetalactone in catnip acts as a feline attractant after it enters the cat's nose. At the olfactory epithelium, the nepetalactone binds to one or more olfactory receptors.
The catnip effect works on the whole cat family, not just on domestic cats. Several tests showed that leopards, cougars, servals, and lynxes often reacted strongly to catnip in a manner similar to domestic cats. Lions and tigers may react strongly as well, but they don't react all the time.
With domestic cats, "N. cataria" is a recreational substance for pets to enjoy. Catnip and catnip-laced products are available to consumers. 
Not all cats are affected by catnip; roughly one third are not affected by the plant. The behavior is hereditary.
Some other plants also have a similar effect on cats, include valerian ("Valeriana officinalis").