An alleged aphrodisiac derived from the bark of the African yohimbe tree. Supposedly causes erection in men and arousal in women but can be very dangerous.

Yohimbine, also known under the outdated names quebrachin, aphrodin, corynine, yohimvetol, and hydroergotocin, is the principal alkaloid of the bark of the West-African tree Pausinystalia yohimbe Pierre (formerly Corynanthe yohimbe), family Rubiaceae (Madder family). There are 31 other yohimbane alkaloids found in Yohimbe.

What is yohimbine? Yohimbine increases the amount of blood that is allowed to flow into the penis and prevents blood from flowing out of the penis. It can cause an erection. Yohimbine is used to treat and diagnose some types of impotence. The PDR reference is here.