Strychnos toxifera
{{Short description|Species of plant in the genus Strychnos}}
{{Speciesbox
|image=Strychnos toxifera - Köhler–s Medizinal-Pflanzen-267.jpg
|image_caption=Botanical illustration
|genus=Strychnos
|species=toxifera
|authority=R.H.Schomb. ex Lindl.Fl. Med.: 530 (1838)
|synonyms=Strychnos syntoxica Sprague & Sandwith
}}
Strychnos toxifera, called bush rope and devil doer, is a species of flowering plant in the genus Strychnos, native to Costa Rica, Panama, Colombia, Ecuador, Venezuela, the Guianas, Brazil, Peru and Bolivia.{{cite web |url=http://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:547525-1 |title=Strychnos toxifera R.H.Schomb. ex Lindl. |author= |date=2017 |website=Plants of the World Online |publisher=Board of Trustees of the Royal Botanic Gardens, Kew |access-date=24 December 2020 }} It is the principal source of calabash or gourd curare.{{cite book |title=CRC World Dictionary of Medicinal and Poisonous Plants: Common Names, Scientific Names, Eponyms, Synonyms, and Etymology |last1=Quattrocchi |first1=Umberto |year=2012 |page=3607 |isbn=9781482250640 }}
Macusine B is an alkaloid inhibitor of adrenergic alpha-receptors and tryptamine receptors that can be isolated from Strychnos toxifera.{{Cite journal|last=Leonard|first=B. E.|date=November 1965|title=The inhibition of adrenergic alpha-receptors and tryptamine receptors by macusine B|url=https://pubmed.ncbi.nlm.nih.gov/4379810/|journal=The Journal of Pharmacy and Pharmacology|volume=17|issue=11|pages=755–757|doi=10.1111/j.2042-7158.1965.tb07600.x|issn=0022-3573|pmid=4379810}}