Syrian Rue: Peganum harmala
Syrian Rue is a MAOI inhibitor which is used to increase the effects of other psychedelic drugs such as LSD, LSA, Mushrooms and DMT. It does have some slight psychedelic effects of its own and did bring on some almost lucid dreaming for me. I did have some of the deepest sleep I have had for a while, but also woke up when I thought I was controlling the lucid dreaming, (I also was on mushrooms at the time.)
It can be obtained easily from eBay and made into a tea for consumption. It has been used as a tea since the times of ancient Persia. About 2 tea-spoons of the seeds will be enough for a nice tea. It is a bit bitter but the use is much worth it. It does have a sedative effect as well so it may make you feel tired. Good for sleeping... but if you are tripping then those effects should out last it and get over your tiredness.
Happy tripping!