Sunday, March 17, 2024

Plant Story--Catnip, Nepeta cataria, a Well-Known Weedy Herb

 Catnip, Nepeta cataria, is one of the better-known little herbs because it is a drug for cats. Cats respond to catnip for about 15 minutes, with distinctive behaviors from rubbing on their faces and rolling in it to grooming and salivating. Young kittens do not respond and some adult cats never do. On the other hand, the response is widespread among cats of all kinds, lions, tigers, cheetahs, lynx, pumas and so on, but not dogs or rabbits or rats or other groups of animals. Since cats are common pets, people provide or grow catnip for them, with the result that catnip is known to many people.

catnip, Nepeta cataria
catnip, Nepeta cataria

Catnip is a mint, in the mint family Lamiaceae, related to spearmint, basil, and sage, the Lamiaceae being a huge family. Catnip's genus Nepeta is native to Eurasia and Africa, with about 250 species. Some other species of Nepeta elicit a response from cats but it is generally weaker than to catnip, because catnip is particularly rich in the compound, nepetalactone, to which cats react. Other Nepeta species have no effect on cats. 

catnip, Nepeta cataria
catnip, Nepeta cataria

Catnip is sometimes called catmint, an accurate name because it is a mint which attracts cats. However, Nepeta cataria is so much more common and widespread than any other member of the genus Nepeta that it is useful to call it catnip, the most popular common name in English, and designate all other Nepeta species as catmints, for example Persian catmint Nepeta racemosa and Japanese catmint Nepeta subsessilis

The scientific name Nepeta is supposed to be based on an Etruscan city, Nepete, modern Nepi, in central Italy, where the plant was very abundant. The species epithet, cataria, is an old name for the plant meaning  "of cats". Cattus does not occur as the word for cat in classical Latin, but by the 6th century it had been added to the language, probably from an unknown African language. Linnaeus picked cataria when giving catnip its scientific name.

Catnip and other Nepeta species have been used as medicines in Europe for more than two millennia. It is often unclear in old herbal writings whether the medicine was catnip or a different, local catmint, though all the Nepeta species tend to share active ingredients.

Catnip is from southern and eastern Europe and was spread widely. The Greeks and Romans recognized the attraction of cats to catnip and grew it for them, as well as using it as a tea and tonic. Romans carried it to northern Europe and Europeans carried it to the world. It quickly escaped and naturalized,  so that in 1843 Beach, in his book on plants and medicine, considered it native. Today it is found in every state except Hawaii and all but Arctic Canada.

catnip, Nepeta cataria

Catnip flowers are about 1/4" in length, white, with reddish or purplish markings in the flower's throat. They are quite attractive to bees. The leaves are slightly fuzzy and give off a gentle minty smell when bruised. The plants produce large numbers of small dark seeds.

Humans have used medicinally for a wide range of ailments. It was used to treat colic, cough, asthma and bronchitis. It was taken as tea as a sedative and to help people sleep. It countered diarrhea and was applied externally to treat hemorrhoids. It was laid on as a poultice to treat swelling. 

Catnip leaves are lightly minty, others call it a lemony-mint flavor, and have been used, fresh or dried, as a traditional flavoring, in juices, salads, soups and sauces, egg dishes and a variety of cooked foods. Today catnip seems mainly reserved for cats, but it is still a valid spice. I drew a blank looking for online recipes for human food flavored with catnip. (I'll check older sources when I get a chance.) The only specific I can give is from second-hand reports that forager Euell Gibbons served candied catnip leaves as an after-dinner digestive aid, dipping each leaf into a mixture of beaten egg white and lemon juice, sprinking each side with sugar, and letting dry for a day or two, then storing them, tightly closed, in the refrigerator until used. 

Most commonly, humans drank catnip tea, which tastes minty, though it is much less intense than spearmint or peppermint, and, apparently, quite volatile so its flavor is easily lost if the water is too hot or the drink  stands neglected for very long. Catnip tea aided digestion and reduced anxiety. The tea produces a mild high in humans. English tradition consequently promoted drinking catnip tea to give courage to even the most timid person. (Tournefort reportedly wrote of a hangman who could not do his duty without fortifying himself by chewing catnip root.) Medical authorities consider catnip tea safe, with no toxicity or undesirable side effects, with the exception that pregnant women should not consume it. 

catnip, Nepeta cataria, seed head
catnip seed head

Studies of catnip's effect on cats show it touches the same sections of the brain that opioids do in humans, though apparently without being addictive. Recent inquiries into the evolutionary origins of the fondness of cats for catnip find that catnip oil is a mosquito repellent. They hypothesize that wild cats that had rolled in catnip were less troubled by mosquitos.

Humans have used catnip as a disinfectant. It was employed to repell rats, though 20th century studies did not find evidence that rats find catnip repulsive. (Maybe the catnip attracted cats and the cats reduced the rats.)

Folklore says that, hung over the door or grown nearby, catnip brings good luck. Hold a catnip leaf or shoot in your hand until it is warm, then hold hands with a person and that person will be your friend forever, provided the catnip you used is kept in a safe place. Large catnip leaves, dried, are the proper bookmarks for magical tomes.

catnip, Nepeta cataria

This is a very common, weedy plant with a long history as a culinary and medicinal herb and with a fascinating relationship with cats. Check out some of the catnip videos online, if you don't have a cat that responds to catnip. (Examples link, link). And consider catnip as a flavoring or tea. Or, just enjoy sniffing it--leaves and flowers--when its growing this spring.

Comments and corrections welcome.

References

Beach, W. 1843. The Family Physician. Published by the Author. New York, New York. online link catnip on p. 693 of Vegetable Materia Medica. 

Cunningham, S. 1993. Cunningham's Encyclopedia of Magical Herbs. Llewellyn Publications, St. Paul, Minnesota. 

Grieve, M. 1932. A Modern Herbal. Dover Publications, New York. 

Gruenwald, J., T. Brendler, and C. Jänicke.  2007. PDR for Herbal Medicines. 4th edition. Thomson Healthcare, Inc. Montvale, New Jersey. 

Hussain,  and others. 2016. Pune-Sa. Nepeta oils. in Essential Oils in Food Preservation, Flavor and Safety, link 

Kowalchik, C. and W. H. Hylton. 1987. Rodale's Illustrated Encyclopedia of Herbs. Rodale Press. Emmaus, Pennsylvania. 

LeStrange, R. 1977. A History of Herbal Plants. Angus and Robertson. London.

Mouthino, S. 2021. Why cats are crazy about catnip. Science.doi: 10.1126/science.abg6551  Link 

Sanders, J. 1993. Hedgemaids and Fairy Candles. Ragged Mountain Press, Cambridge, Maine. 

Tucker, A. O. and S. S. Tucker. 1987. Catnip and the catnip response. Economic Botany. 42: 214-231.

Uenoyama R, et al. (2021). The characteristic response of domestic cats to plant iridoids allows them to gain chemical defense against mosquitoesScience Advances7 (4): eabd9135. link 

Kathy Keeler
A Wandering Botanist



2 comments:

  1. Thoroughly enjoyed your post! Your perspective is refreshing. Keep up the great work and write more! Get involved in discussions about the Aviator game on our blog.

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  2. I have never understood how the scent of Nepeta cataria can be described as minty or lemony. To me, it is an extremely unpleasant, skunky aroma. I let it grow here and there in my yard as gifts for my friends' cats, and because it's foliage is beautiful (the flowers are rather nondescript). I think this year I'll try making it into a tea, because I can't imagine the drink such a noxious-smelling plant would make!

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