The Collaborative International Dictionary of English v.0.48:

Fructuous \Fruc"tu*ous\, a. [L. fructuosus: cf, F. fructueux.]
   Fruitful; productive; profitable. [Obs.]
   [1913 Webster]

         Nothing fructuous or profitable.         --Chaucer.
   -- Fruc"tu*ous*ly, adv. -- Fruc"tu*ous*ness, n. [Obs.]
   [1913 Webster]