ephemeral

/ɪˈfɛm.ər.əl/

adjective

  1. Lasting for a very short time; fleeting, transitory, or impermanent. "The cherry blossoms bloomed in an ephemeral burst of pale pink before the spring rain scattered them."
  2. (Biology) Having a very brief life cycle, such as an insect living only for a day or a desert plant blossoming immediately after rainfall. "Ephemeral desert wildflowers complete their entire reproductive cycle in a matter of days."

noun

  1. Something of transitory value, existence, or interest, such as dayflies or temporary printed matter. "Archivists treasure nineteenth-century concert tickets and newspaper advertisements as historical ephemera."