[size=75]From Wikipedia, the free encyclopedia [/size]
Nepeta is a genus of about 250 species of flowering plants in the family Lamiaceae. The members of this group are known as catnips or catmints due to its famed liking by cats—nepeta pleasantly stimulates cats’ pheromonic receptors. The genus is native to Europe, Asia, and Africa, with the highest species diversity in the Mediterranean region east to mainland China. It is now common in North America as a weed. Most of the species are herbaceous perennial plants, but some are annuals. They have sturdy stems with opposite heart-shaped, green to grayish-green leaves. The flowers are white, blue, pink, or lilac and occur in several clusters toward the tip of the stems. The flowers are tubular shaped and are spotted with tiny purple dots. The scent of the plant has a stimulating effect on cats.
Oil isolated from catnip by steam distillation is a repellent against insects, in particular mosquitoes, cockroaches and termites. Research suggests that in a test tube, distilled nepetalactone, the active ingredient in catnip, repels mosquitoes 10 times more effectively than DEET, the active ingredient in most insect repellents, but that it is not as effective as a repellant on skin.
Catnip is also smoked by humans. It is reported to have a very mild sedative effect and is often added to legal herbal non-tobacco smoking mixtures.
Both true catnip and Faassen’s catnip have a sharp, biting taste, while the taste of giant catmint is bland.
Catnip and catmints are mainly known for the behavioral effects they have on cats, particularly domestic cats. When cats sense the bruised leaves or stems of catnip, they may roll over it, paw at it, chew it, lick it, leap about and purr, often salivating copiously. Some cats will also growl and meow. This reaction only lasts for a few minutes before the cat loses interest. It takes up to two hours for the cat to “reset” after which it can come back to the catnip and have the same response as before. Young kittens and older cats are less likely to have a reaction to catnip.
Approximately two thirds of cats are susceptible to the behavioral effects of catnip. The phenomenon is hereditary; for example, most cats in Australia are not susceptible to catnip, since Australian cats are drawn from a relatively closed genetic pool. That it only elicits such a response in a proportion of cats—and that it is such a dramatic response—suggests that a genetic element is involved that is enriched in domesticated breeds. There is some disagreement about the susceptibility of lions and tigers to catnip. Some claim that all lions and tigers are affected by catnip, but others say lions are affected but not tigers.
Catnip contains nepetalactone, a terpene. Nepetalactone can be extracted from catnip using steam distillation. Cats detect it through their olfactory epithelium and not through their vomeronasal organ. At the olfactory epithelium, the nepetalactone is hypothesized to bind to one or more olfactory receptors where it probably mimicks a pheromone, such as the hypothetical feline facial pheromone.