Calea zacatechichi is a Mexican herb commonly used in folk medicine to treat dysentery, fevers, gastrointestinal complaints and respiratory disorders such as asthma.  
The native Chontal people of Oaxaca call it thle-pela-kano, and use it for divination rituals which involve smoking the plant, drinking it as a tea, and placing it under a pillow to induce divinatory dreams.
Current popular use confirms Calea leaf is a viable smoking alternative, giving a dreamy effect. As a tea it may induce lucid dreaming. The following day, some ‘lucid dreamers’ report feeling a wonderful sense of wellbeing and clarity of mind and senses.