Curare [koo rah ree] [1] is a common name for various dart poisons (arrow poisons) originating from South America. The three main types, or families of curare are:
the tubocurare (also known as tube or bamboo curare, because of its packing into hollow bamboo tubes; main toxin is D-tubocurarine). It is a mono-quaternary alkaloid, an isoquinoline derivative.
the calebas curare (also called "gourd curare" by older British classifications, being packed into hollow gourds; main toxins are alloferine and toxiferine)
and the pot curare (packed in terra cotta pots; main toxins are protocurarine, protocurine, and protocuridine).
Curare is an example of a non-depolarizing muscle relaxant (aka, competitive antagonist) which blocks the nicotinic acetylcholine receptor, one of the two types of cholinergic (acetylcholine) receptors, on the post synaptic membrane of the neuromuscular junction. Curare does not occupy the agonist position, but likely binds within the channel pore.