Key to the families (Loranthaceae and Viscaceae)

1Perianth monochlamydeous, with tepals mostly less than 2 mm long; flowers unisexual, with male and female flowers usually in the same inflorescence; pollen spherical; fruit with the viscous layer inside the vascular bundles; embryo suspensor very short or absent
1'Perianth dichlamydeous, with the calyx reduced to a limb at the apex of the ovary and the corolla (2.5-)10-150 mm long; flowers mostly bisexual, rarely functionally unisexual and then with vestigial organs of the other sex present and plants mostly dioecious; pollen trilobate; fruit with the viscous layer outside the vascular bundles; embryo suspensor long, multiseriate