Ilex guayusa

Ilex guayusa, commonly known as "guayusa", is a tree of the Yaupon Holly (the plant used to make the "black drink"). The leaves have the highest caffeine content of any known plant.

The leaves are boiled to produce a tea; due to the high caffeine content, the same leaves are often used multiple times, sometimes for several days. Fresh leaves are used as well as dried leaves, which are dried in rolls and strung together as a wreath resembling a Hawaiian lei.

In addition to the stimulant effects, the tea is used to enhance dream recall. To achieve this effect, it is believed that the tea must be drunk consistently in the early morning, just after waking, before the sunrise. For many Ecuadorian indigenous, the morning drinking of guayusa is a social ritual.

In areas in which it grows, it is also a common admixture to the powerful hallucinogenic on its own, when drunk in high enough quantities. The plant can "contain more than 2.0% caffeine."^[2]

Guayusa is sold under the brand name "Qat Tea™", but is unrelated to the stimulant plant known as qat.[1]