(K.Schum.) Pierre ex Beille
Pausinystalia johimbe, (Rubiaceae), common name Yohimbe, is a plant species native to western and central Africa (Nigeria, Cabinda, Cameroon, Congo-Brazzaville, Gabon, Equatorial Guinea). Extracts from yohimbe have been used in traditional medicine in West Africa as an aphrodisiac and have been marketed as dietary supplements The active ingredient in the extract, yohimbine, is a veterinary drug and has been studied as a potential treatment for erectile dysfunction but there is insufficient evidence to rate its effectiveness.
Yohimbe is one of five Pausinystalia species, which are evergreen. It grows in West and Central Africa in lowland forests. The tree grows about 30m tall, with a straight bole that is rarely larger that 50-60 cm in diameter. The bark is grey to reddish-brown, with longitudinal fissures. It is easy to peel and bitter-tasting. The inner bark is pinkish and fibrous. The sapwood is yellowish and the heartwood is ochre-yellow; the wood is fine-grained and relatively dense and moderately hard. The leaves grow in groups of three, with short (about 2 cm) stems. The blades are oval-shaped, 11-47 cm long and 5 - 17 cm wide. 
The demand for yohimbe bark has led to over-exploitation and possible long-term endangerment. Cameroon is the biggest exporter.
The wood and bark are used for firewood and construction. The bark is the most commercially important product, used locally and for export for traditional medicine and dietary supplements.
Yohimbe extract is widely used as a dietary supplement. By itself, yohimbe bark is on the FDA list of banned substances. Yohimbe bark is also currently banned in the UK, Ireland, Belgium, the Netherlands, Australia, New Zealand, Denmark, the Czech Republic, and Canada.
The active ingredient in the extract is yohimbine; it is a veterinary drug used to reverse sedation in dogs and deer. In addition to yohimbine, yohimbe extract contains about 55 other alkaloids. Yohimbine accounts for 1-20% of its total alkaloid content. Among the others is corynanthine, an alpha-1 adrenergic receptor blocker.
The levels of yohimbine that are present in yohimbe bark extract are variable and often very low. In addition to the main active chemical, yohimbine, Pausinystalia yohimbe contains approximately 55 other alkaloids, of which yohimbine accounts for 1% to 20% of total alkaloids.
The epithet "johimbe" is often misspelled "yohimbe" including by Beille in his 1906 recombination statement formally transferring the species from Corynanthe. Schumann's original 1901 description used the spelling "johimbe," and Beille clearly cited Schumann's name as basionym. Therefore "yohimbe" used as a formal specific epithet is a spelling error to be corrected per article 60.1 of the ICN. No such rules, of course, apply to common names.
- Kew World Checklist of Selected Plant Families, Pausinystalia johimbe
- Beille, P. E. (2013). "Scientific Opinion on the evaluation of the safety in use of Yohimbe (Pausinystalia yohimbe)". EFSA Journal 11. doi:10.2903/j.efsa.2013.3302.
- "Yohimbe: MedlinePlus Supplements". Medline. Retrieved 2013-05-26.
- R.b. Jiofack Tafokou. Pausinystalia johimbe. pp 516-519 in Timbers Volume 2; Volume 7 of Plant Resources of Tropical Africa. Eds. Lemmens, R.H.M.J., Louppe, D. & Oteng-Amoako, A.A., G.J.H Grubben. PROTA Foundation, 2012. ISBN 9789290814955
- "Yohimbe Bark Supplements for ED: Side Effects, Safety, Dangers, and More". Webmd.com. 2012-08-06. Retrieved 2013-05-26.
- 21 CFR Sec. 522.2670 Yohimbine
- Doxey, JC; Lane AC; Roach AG; Virdee NK (Feb 1984). "Comparison of the alpha-adrenoceptor antagonist profiles of idazoxan (RX 781094), yohimbine, rauwolscine and corynanthine.". Naunyn-Schmied Arch Pharmacol 325 (2): 136–144. doi:10.1007/bf00506193. PMID 6144048.
- Pierre, Jean Baptiste Louis & Beille, Lucien. 1906. Actes de la Société Linnéenne de Bordeaux 61: 130
- Schumann, Karl Moritz. 1901. Notizblatt des Botanischen Gartens und Museums zu Berlin-Dahlem 3: 94, 95