Hello, we used a phylogenetic framework, but also you can distinguish them through morphological traits and chromosome number. You can review the papers Santos-Gally et al 2012 JofB and  Diaz-Lifante et al 2009 for more details. I hope that helps. 

thank you very much for your email. We prepare a paper about narcissus serotinus that grow in Anatolia. We knew that, it is N. seratinus, but it isn't.

it is N. obsoletus . We distinguish chromosome number. It is 2n 30, so We also wants distinguish morphological traits. Which character should I use?

Several Narcissus species are polymorphic for style length and connsiderale work on genetics of heterosrtly has been done. I wonder if the various forms differ in their fragrances.

We analyzed several individuals of different style-morph for one species and we did not find differences. The difference are among species of the genus. We soon submitted those results.

Thanks alot