stavesacre

noun

staves·​acre ˈstāv-ˌzā-kər 

1

: a poisonous herbaceous biennial Eurasian plant (Staphisagria macrosperma synonym Delphinium staphisagria) that has a hairy stem, large palmate leaves, and blue or purple flowers

2

a

: the seeds of the stavesacre that contain delphinine, are emetic and cathartic, and have been used in various topical preparations (such as to kill head lice, sooth irritated skin, and promote wound healing)

b

: a preparation (such as a tincture) made from the seeds of the stavesacre : staphisagria