As it only blooms for one day it represents the fleeting nature of love or of unrequited love.
According to Chinese folklore, Chien Niu, a boy was given the responsibility to take care of water buffalo. Chih Neu a girl was entrusted with the task of making dresses. They fell in love, and eventually started ignoring their duties. God was really furious and separated both of them on the other side of the silent river, letting them meet only once a year. The morning glory symbolizes their tale.
The seeds are hallucinogenic.