They are either perennializing, or naturalizing. Perennializing bulbs will grow back for several years. Naturalizing bulbs will grow back every year.
There are four different types: corms, true bulbs, tubers, and rhizomes.
A corm is made up of solid tissue. They are a storage organism that can hold up in the toughest summer and winter weather. An example of a corm is freesia.
A true bulb is made up of layers that house an embryo of the actual plant to be planted. Tulips are true bulbs.
Tubers are a mass of tissue that stores the plants nutrients. Calla lilies are a type of tuber plant.
A rhizome is a stem of a plant that grows horizontally. Canna is a type of rhizome.
Below are listed several different types of bulbs. Look over each one to decide what works best for your area, soil, and of course which ones you like best!
Below is a list of some great Flower Bulbs: