mushroom-like
/ˈmʌʃruːmlʌɪk/ /ˈmʌʃrʊmlʌɪk/adverb
In a manner likened to that of a mushroom, with reference to rapid growth, sudden appearance, or brief duration of existence.
adjective
Resembling a mushroom, especially in shape or colour.
Origin
Early 17th century; earliest use found in William Slatyer (c1587–1647), Church of England clergyman and author. From mushroom + -like.