The Collaborative International Dictionary of English v.0.48:

Florescent \Flo*res"cent\, a. [L. florescens, p. pr. of
   florescere begin to blossom, incho. fr. florere to blossom,
   fr. flos, floris, flower. See Flower.]
   Expanding into flowers; blossoming.
   [1913 Webster]