Etymology of Mushroom

In the sixteenth century this word appears generally to have been spelt *Mushrump*. Nares, in his valuable *Glossary*, gives an instance from Marlow's play of *Edward the Second*, 1598; but there is an earlier example in Robert Southwell's *Spirituall Poems*, 1595: "He that high growth on cedars did bestow, Gave also lowly *mushrumps* leave to growe." It is also spelt *Mushrump* in Cockeram's *Dictionary*, 1632. These instances may possibly lead to a correct etymology of the word.