Although all of the plants listed here have aromatic roots, most of them are better known as herb or fruit spice. If you look for a specific root spice and can't find it here, then maybe it's not a root but a rhizome . However, some subterranean fleshy stems known as rootstocks or rhizomes, form valuable spices. And, there are some aromatic barks as well. In case of herbs, it is rather common to harvest stem, leaves and possibly flowers together, although the leaves are the most fragrant part.
Bulbs are special subterranean reserve structures derived from leaves.
Although most insectophil flowers are somewhat fragrant, only few of them are used in the kitchen, because they usually lose their scent quickly when dried. The ripe form of flowers, fruits, are also frequently aromatic, but mostly not to attract insects but to repel them.