I've often wondered why similar flower fragrances crop up in entirely unrelated species. Confederate jasmine
(Trachelospermum jasminoides) is
in bloom now and its perfume is the same as sweet William
(Dianthus barbatus) and some petunias.
Unintentionally, I seem to have wound up with a lot of fragrant plants; perhaps that's because the tropics offer such an enormous variety. Of course, I have a gardenia. I also have lady of the night
(Brunfelsia nitida), Dracaena fragrans 'Massangeana,' four o'clock
(Mirabilis jalapa), frangipani
(Plumeria sp.), various true jasmines, confederate jasmine and more.
Anyway, I asked my friend Scott, a neighborhood botanist and gardener, about the similarity of fragrances and he said that it's determined by the type of pollinator. Scented white flowers, for instance, are usually pollinated at night by moths. I had been wondering if there was a limited number of scents available to the plant world, but he said that there were thousands of compounds that plants use. (Ranging from the divine to the disgusting.)
I reckon nothing beats a damask rose, an Arabian jasmine
(Jasminum sambac) or orange blossom for fragrance. Sadly, their essential oils are too expensive to use with abandon.
And some fragrances are simply overpowering. The night scented/blooming jasmine
(Cestrum nocturnum) is an example and I can't tolerate being close to it; I like it about two blocks away. Even the good old gardenia doesn't seem to know when enough is enough.