
1) The seeds themselves
Found on
https://www.crosswordclues.com/clue/stavesacre

• (n.) A kind of larkspur (Delphinium Staphysagria), and its seeds, which are violently purgative and emetic. They are used as a parasiticide, and in the East for poisoning fish.
Found on
http://thinkexist.com/dictionary/meaning/stavesacre/
Staves'a`cre noun [ Corrupted from New Latin
staphis agria , Greek ... dried grape + ... wild.]
(Botany) A kind of larkspur (
Delphinium Staphysagria ), and its seeds, which are violently purgative and emetic. They are used as a parasiticide, and in the East for poisoning fish.
Found on
http://www.encyclo.co.uk/webster/S/189

a larkspur, Delphinium staphisagria, of Europe and Asia Minor, having violently emetic and cathartic poisonous seeds. · the seeds themselves.
Found on
https://www.infoplease.com/dictionary/stavesacre
No exact match found.