I consider giving flowers as a very romantic thing :)
I tend to surprise my significant other with flowers on random occasions. I love surprising her (non-existent at the moment) with anything I deem worthy of a gift for her. I’ve found that treating your loved one not only makes it a much more loving bond and ambiance, but it also creates a habit of remembering the small details most of us take from granted after a while. There is nothing I love more than seeing my loved ones smiling.
I actually do not have a favorite type of plant / flower. I’m not one to expect such gifts (I’m a dude, after all. Lol). This doesn’t mean that I wouldn’t welcome the gesture. I’m not too manly to be greeted with such a considerate act. I just wouldn’t be the type to ask for it or expect it lol. I’d rather be surprised with tacos or beers… or both :-P