Vintage, Flora Full Length Dress

The label is missing, I bought this dress for one of our charity events held at the Beverly Wishire Hotel, in the late 80's maybe early 90's.  

I have been convinced, all these years, that this is a Diane von Furstenberg dress, however I stand corrected. If anyone out there can assist me in identifying the designer of this dress, it would be greatly appreciated. 

Fabric: 100% Cotton 

Colour: Multi

Size: S