Never thought about it. Mayby I`m not sophisticated enough in botany.
Подсолнухи \ подсолнечники - I would use any, depending on my mood.
Even if it is not 100% correct.



Same stuff: Пожарный vs Пожарник
Ordinary people use them both, assuming a fire fighter. But a real fire department worker may be offended on the second one.
Пожарный = Fire fighter
Пожарник = Arsonist