Citronellyl formate smells green, rosy, slightly fruity with a tropical aspect (some say apricot, others pear)
 
I used to not like this one so much. When first smelling it, it's not uncommon to have the feeling that it's all the worst parts of citronelicity.
It doesn't have the floralcy or the smooth rosiness that you get with a high-quality citronellol or l-citronellol.
 
But formate esters have something else, and that's an immense power and sharpness. In the case of citronellyl formate that comes across as a greener, fresher sort of rosiness as well as a pointedness that makes it very suited to tropical themes such as kiwi, star fruit (where it occurs naturally), and of course geranium (where a few percent is to be expected in the leaf oil).