This Acanthaceae, known as toe negro (cf. Brugmansia
suaveolens) , is used by the Colombian
Kokama Indians both as an ayahuasca additive
and as a psychoactive substance in its own right.
For this purpose, ten leaves are boiled for seven
hours over a low flame. The effects are said to be
strong. A person loses his or her vision for three
days, but during this time he or she can communicate
with the spirit of the plant (Schultes
1972, 139*). Chemical studies of the plant have
demonstrated that the leaves are devoid of alkaloids
(Ott 1993, 402*). The plant is added to
ayahuasca only when it is intended for use in
"witchcraft" (Duke and Vasquez 1994, 167*).