liverwort n.

secreting organ of the body, Old English lifer, from Proto-Germanic *librn (source also of Old Norse lifr, Old Frisian livere, Middle Dutch levere, Dutch lever, Old High German lebara, German Leber "liver"), perhaps from PIE root *leip- "to stick, adhere," also used to form words for "fat."

Formerly believed to be the body's blood-producing organ; in medieval times it rivaled the heart as the supposed seat of love and passion. Hence lily-livered, a white (that is, bloodless) liver being supposed a sign of cowardice, Shakespeare's pigeon-livered, etc. Liver-spots, once thought to be caused by a dysfunction of the organ, is attested from 1730.

"a plant," Old English wyrt "root, herb, vegetable, plant, spice," from Proto-Germanic *wurtiz (source also of Old Saxon wurt, Old Norse, Danish urt, Old High German wurz "plant, herb," German Wurz, Gothic waurts, Old Norse rot "root"), from PIE root *wrād- "branch, root." St. John's wort attested from 15c.