Light green petals together with the bright orange-rimmed green cup unmistakably reveal its viridiflorus parentage. Long lasting, scented flowers is another trait it inherited.
If you'd like to try some hybridising with green daffodils, this is one you should try as it is fertile. 
 
(relatively untested for hardiness. Withstood couple of degrees of frost outside in a pot)
(photo courtesy of Nijssen)