It's not for nothing that tulips are the second most popular flower sent on Valentine's Day.

Tulips stand for perfect love, according to ProFlowers, and their various colors have different shades of meaning.

Red: a sign of true and undying love

Purple: forever love

White: one-sided love

Yellow: the meaning has evolved from representing hopeless love to being a common expression for cheerful thoughts and sunshine.

--Cathy Jett