Multiple choice Which of the following plant genera has coralloid root? Cycas Vinca Dahlia Rose Pomegranate Reveal answer Fill a bubble to check yourself A Correct answer Explanation Roots in some genera of gymnosperm have fungal association in the form of mycorrhiza (Pinus) while in some others (Cycas), small specialised roots called coralloid roots are associated with nitrogen fixing cyanobacteria, i.e. cycas.