Matthew and Mark have καλάμῳ, a reed. Luke says merely that they offered Him vinegar. The vinegar mingled with gall (Mat 27:34), or the wine mingled with myrrh (Mar 15:23) was offered to Jesus before his crucifixion as a stupefying draught. The hyssop gives a hint of the height of the cross, as the greatest length of the hyssop reed was not more than three or four feet. The vinegar in this case was offered in order to revive Christ. John does not mention the stupefying draught.