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Djombe - Idagbon - Gabo - Endone
West and Central Africa
West and Central Africa
1. Species identity
Scientific name: Pausinystalia johimbe (K. Schumann) Pierre ex
Common name: johimbe, yohimbe
Vernacular name: (Cameroon) Djombe, Adjeck, Atyek; (Nigeria)
Idagbon; (Congo) Gabo; (Gabon) Endone
trunk (Bark Harvest)
• Botanical description
Evergreen tree which can grow up to 30-35 m tall and
30-60 cm wide with ternate vegetative and generative
ramification. The bark, 4-10 mm thick cracks in furrows; Stem is cleared of branches from the base up to
a length of 10-20 m depending on the tree height;
Leaves have petioles up to 5 mm long; they are whole,
opposite, glabrous, obovate, cuneate or rounded and
sometimes angustate or cordate at the base; Flowers
build up to an inflorescence (of white flowers) at the
top or at the side, firm stipules at the base; Fruits are
Botanical illustration of P. johimbe (drawn by Lucy T. Smith)
2. Ecology and distribution
• Natural habitat and geographical
Occurs naturally in Atlantic Biafran Evergreen Ceasalpiniaceae forest; a contiguous vegetative formation extending from SE Nigeria through Cameroon, Equatorial Guinea, Gabon, Congo and
Democratic Republic of Congo. It is most common
in coastal forests although not widespread throughout its range. It is endemic to its region.
• Reproductive Biology
The reproductive system is entomophilous (operated by insects). The seeds are wind dispersed
and their lightness and winged structure facilitates their spread over long distances. The tree
flowers in August for the most precocious trees, and fruits in October. Fruits mature during the
dry season in Cameroon (between November and February).
• Fibre: Strands from the inner bark are used as straps for animal packs (game bag).
• Fuel and Timber: The young poles are used for construction. The fibre is used to set
traps for animals due to its flexibility.
• Poison: Poisonous doses of yohimbe are reported to paralyze respiration and the drug
can cause severe hypotension, abdominal distress and weakness. It can also be used as
an ichthytoxicant (fish poison).
• Medicine: The bark contains up to 6% of a mixture of alkaloids, the main one being
yohimbine, which is also known as aphrodine. P. johimbe, is the source of the only clinically-proven cure for impotence. The vasodilating action of yohimbe is particularly strong
on the sex organs, hence its aphrodisiac properties. P. johimbe is also used as a local pain
reliever, a mild stimulant to prevent drowsiness, a hallucinogen, a treatment for sore
throat, a hypotensive, a general tonic, a performance enhancer for athletes, a remedy to
increase the clarity of the voices of singers
during long festivals and as a treatment to
increase the resistance of hunting dogs. It is
Johimbe bark and phatrmaceutical products
taken in two forms: powder (ground bark)
and liquid (bark boiled in water).
• Intercropping: Because P. johimbe is a middle-story tree, it has the potential to be an
ideal species for farmers to grow in their fields in multi strata systems.
4. Propagation Methods
Seeds of P. johimbe are orthodox. They can lay dormant in the seed bank
for some time and germinate only when the red/far red light ratios change.
The seedlings grow very slowly and the low survival rate of plants after potting makes it difficult to propagate he species. Collecting the seeds is also
a perikous task.
4.2. Rooting of cuttings
• Rooting medium: Sawdust
• Leaf area: 50 cm2
• Cutting length: 4 to 6 cm
• Treatment: 150
g and 200
g of IBA (Indole – butyric acid)
• Rooting: 2 weeks after setting
• Rooting success rate: more than 70% after 11 weeks
• Survival rate: about 80%
• Potting medium after rooting: 2:1 mixture forest soil
• Size of polythene bags: 1 litre
5. Planting and Management
The seed and seedlings need light for their development. Under too much sun, they rapidly dry
up and die. The older stems (>3 m high or 5 cm dbh), however, are able to grow and reproduce
in high light situations suggesting their suitability for inclusion in both agroforestry and monoculture systems. optimum period for seed collection in both Cameroon and Equatorial Guinea is
This fast growing tree never reaches great diameter, with the maximum being 50 cm dbh. The
ability of the species to coppice well, producing strong, highly phototrophic shoots, after being
felled enhances sexual reproduction and therefore the propagation of P. johimge by rooting of
cuttings. Bark exploitation is a seasonal activity as the yohimbine levels reach their peak during
the rainy season.
6. Pests and diseases
Although P. johimbe trees regenerates well after a small amount of bark harvest. The removal
of large quantities of bark can however lead to an attack by a small stem borer which penetrates the unprotected stem, killing the tree.
Bibliography and Further Reading
• M-L., Mpeck. 2005 Contribution to the Domestication of High-Value tree Species: Case of
Pausynistalia johimbe (K. Schum.) Pierre ex Beille (Rubiaceae). Ph.D. Thesis
• http://www.worldagroforestrycentre.org/ sea/Products/ AFDbases/AF/
a s p / SpeciesInfo.asp?SpID=1733
• Illustrations : Lucy T. Smith, World Agroforestry Centre-West and Central Africa Region.
Régine Pakeujou Tchientche
Dr. Zac Tchoundjeu
For more information contact :
World Agroforestry Centre-West and Central Africa
Regional Office P.O. Box 16317 Yaounde-Cameroun
Tel: (237) 184.108.40.206 / 220.127.116.11
Fax: (237) 18.104.22.168 / 22.214.171.124
E-mail: [email protected]
Web site : worldagroforestrycentre.org/aht