Hydrangea
Hydrangeas come in bunches of 5 blooms. The primary colors are blue, pink, purple/lavender, mauve, green and white. The colors are not real pure so always think lavenderish as opposed to lavender. I cannot stress enough that you need to be EXTREMELY flexible on hydrangea colors. For most arrangements you will need 3-6 blooms. They are available from late May to mid October.