ef ‧ flo ‧ res ‧ cence /ˌefləˈres ə ns/ BrE AmE noun [uncountable] literary
[ Date: 1600-1700 ; Language: French ; Origin: Latin efflorescere 'to come into flower' , from flos ; ⇨ ↑ flora ]
the action of something forming and developing, or the period of time when this happens:
There was an efflorescence of scientific publication in the period 1645-1660.