The sunflower is an annual plant in the family Asteraceaeis. There are several varieties. The sunflower is a single stalked flower that produces seeds. The seeds are much used for feeding parrots, wild birds, and various pets such as rats, mice and hamsters, etc., as part of a mixed diet. The seeds can be used in cooking and will be on sale in health stores, either as seeds or as an oil. So, in a way, it is a kind of herb in cooking, but definitely not a shrub or a tree.