Nepeta is a genus of about 250 species of flowering plants in the family Lamiaceae. The members of this group are known as catnip or catmint because of their famed effect on cats—nepeta pleasantly stimulates cats' pheromonic receptors, typically resulting in the animal temporarily exhibiting behaviors indicative of being in an induced, euphorically giddy sort of state.
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 also common in North America. 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 and 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 ten times more effectively than DEET
, the active ingredient in most insect repellents, but that it is not as effective as a repellent on skin. Additionally, catnip and catnip-laced products designed for use with domesticated cats are available to consumers. Catnip mixed together with chamomile tea
can be used to lighten the color of hair.
Effects on cats
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 react 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. It elicits such a response in only some cats, because 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 the way lions and domestic cats react to catnip suggest further evidence of the genetic existence of a susceptibility to catnip outside of domestic felines.
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 mimics a cat pheromone, such as the hypothetical feline facial pheromone or the cat urine odorant MMB.
Other plants that also have this effect on cats include valerian (Valeriana officinalis) and plants that contain actinidine or dihydroactinidiolide (Smith, 2005).
- Nepeta cataria (Catnip, True Catnip, Catmint or Field Balm) is a 50–100 cm tall herb resembling mint in appearance, with greyish-green leaves; the flowers are white, finely spotted with purple. It has been introduced to many countries, including the United States. A lemon-scented cultivar, N. cataria 'Citriodora', looks exactly like true catnip but has the scent of lemons and can be used like Lemon balm.
- Nepeta grandiflora (Giant Catmint or Caucasus Catmint) is lusher than true catnip and has dark green leaves and dark blue, almost purple flowers.
- Nepeta × faassenii (N. racemosa × N. nepetella; Faassen's Nepeta or Faassen's Catnip) is mostly grown as an ornamental plant. This hybrid is far smaller than either of above and is almost a ground cover. It has greyish-green leaves and light purple flowers.
- Some Dracocephalum, Glechoma and Calamintha species were formerly classified in Nepeta.
- Nepeta species are used as food plants by the larvae of some Lepidoptera (butterfly and moth) species including Coleophora albitarsella.Selected species
- Nepeta agrestis
- Nepeta annua
- Nepeta apuleii
- Nepeta beltranii
- Nepeta camphorata
- Nepeta cataria
- Nepeta ciliaris
- Nepeta coerulescens
- Nepeta curviflora
- Nepeta densiflora
- Nepeta dentata
- Nepeta dirphya
- Nepeta discolor
- Nepeta elliptica
- Nepeta everardi
- Nepeta floccosa
- Nepeta foliosa
- Nepeta fordii
- Nepeta glutinosa
- Nepeta govaniana
- Nepeta granatensis
- Nepeta grandiflora
- Nepeta heldreichii
- Nepeta hemsleyana
- Nepeta hindost
- Nepeta hispanica
- Jacobs, Betty E.M. Growing and Using Herbs Successfully. Garden Way Publishing. Pownal, Vermont, 1981.