Cempasúchil comes from the Nahuatl language and refers to the marigold flower in spanish. The origin story of why marigolds are held in such reverence in Mexican folklore, especially during Dia de los Muertos, is a surprisingly sweet one. Xochitl and Huitzilin fell in love and one day climbed to the top of a tall hill to leave offerings for the sun god, Tonatiuh. They asked him to bless their love with prosperity. Soon after Huitzilin was called to war and subsequently died in battle. Xochitl was so devastated she returned to the hill to ask Tonatiuh to reunite her with her love. Tonatiuh agreed and transformed her into a marigold and Huitzilin into a hummingbird. The bright and colorful marigold attracted the lost soul of Huitzilin and their love blossomed once again.
This is why you see marigolds everywhere during October. They help guide and attract the souls of passed loved ones to return to us so that we can remember and honor them.