First discovered in Japan, the name hydrangea comes from the Greek "hydor," meaning water, and "angos," meaning jar or vessel. This roughly translates to "water barrel," referring to the hydrangea's need for plenty of water and its cup-shaped flower. With its wooden stems and lacy, star-shaped flowers packed closely together in a pompom, the hydrangea's color ranges from white to blue to pink and purple, determined by the acidity level of the soil.
There remains some debate over the hydrangea's symbolism – with some connecting it to vanity and boastfulness (perhaps reflecting its abundance of petals and lavish, rounded shape) and others suggesting that a bouquet of hydrangeas expresses the giver's gratefulness for the recipient's understanding. Still others suggest it represents anything that's sincerely heartfelt. Despite this variation in flower meaning, there appears to be an overwhelming consensus that this 4th wedding anniversary flower possesses enduring grace and beauty.