Why do heavenly blue morning glories act as hallucinogens? what about the other types of morning glories, do they do the same thing or just the blue?

Morning glory seeds: Heavenly blue morning glories come in multiple colors: blue, purple, pink, and white. The seeds in all of them contain the hallucinogenic chemical d- lysergic acid (lsa, or ergine) -- closely related to lsd, but less potent. It's a tryptamine that causes altered perceptions, thinking & mood along with intense nausea, vomiting, and abdominal pain. They were also used in ancient aztec rituals.