St. John's wort

plural St. John's worts · alternative St John's wort · alternative Saint John's wort

1. uncountableusuallyAny of several plants, of the genus Hypericum, especially Hypericum perforatum, that have yellow flowers and traditionally ward off evil.

   that hearbe we call S. John]

   [1612, Michael Drayton, Poly-Olbion song 13 p. 218http://poly-olbion.exeter.ac.uk/the-text/full-text/song-13/

   3 more examples

   It is also necessary to watch cattle so that they may not graze in any place where the Elle-people have been. If any animal goes to a place where the Elle-people have spit or done what is worse, it is attacked by some grievous disease, which can only be cured by giving it a handful of St. John's wort, which was pulled at twelve o'clock on St. John's night.

   1828, Thomas Keightley, The Fairy Mythology, volume I, London: William Harrison Ainsworth, page 140

   Peony would keep away any kind of storms. Mugwort hung over doorways on Midsummer's Day, June 24, would keep off lightning, as St. John's-Wort would if gathered before sunrise on that day.

   1940, Rosetta E. Clarkson, Green Enchantments: The Magic Spell of Gardens, The Macmillan Company, page 258

   Athletes' use of herbal supplements has skyrocketed in the past two decades. At the top of the list of popular herbs are echinacea and ginseng, whereas garlic, St. John's wort, soybean, ephedra and others are also surging in popularity or have been historically prevalent.

   2013 March 28, David S. Senchina, “Athletics and Herbal Supplements”, in American Scientist, volume 101, number 2, archived from the original on 16 May 2013, page 134

   Synonyms: common St. John's wort, John's wort, springwort

2. uncountableusuallyThe plant prepared as a medication.