Wild garlic, called sorcerer's garlic. There are many sorts, all of which flower in May, except “the sweet moly of Montpelier,” which blossoms in September. The most noted are “the great moly of Homer,” the Indian moly, the moly of Hungary, serpent's moly, the yellow moly, Spanish purple moly, Spanish silver-capped moly, and Dioscorides's moly. Pope describes it and its effects in one of his odes, and Milton refers to it in hisComus. (Greek, molu.)
That moly That Hermes once to wise Ulysses gave.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894