Properties in Passionfruit can be used as a sleep aid. The fruit contain traces of the sedative compound harman. According to National Institute of Health, Harman has traditionally been used to treat anxiety, insomnia, and restlessness.
Palmyra Palm is available in Africa, Asia, and New Guinea. With a hard shell similar to a coconut, it is difficult to get into. This video shows how it's done in Bangladesh. I probably wouldn't try this at home!