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Tetrorchidium didymostemon (Baill.) Pax & K.Hoffm.

Engl., Pflanzenr. IV, 147, 14: 53 (1919).
Chromosome number
n = 33
Tetrorchidium minus (Prain) Pax & K.Hoffm. (1919).
Vernacular names
Arbre à savon du Gabon (Fr). Pau branco, pau gamela (Po).
Origin and geographic distribution
Tetrorchidium didymostemon occurs from Guinea Bissau east to Uganda and south to Tanzania and Angola.
Throughout its distribution area the latex from the stem bark is used as eye drops to treat filariasis, and is also applied to abscesses, leprous sores and glandular swellings. Leaf sap is applied to wounds as a haemostatic. The leaf sap in water or rum, or a stem bark decoction, is commonly taken as a purgative and to treat fever. To treat constipation or enlarged spleen in babies, leaf sap is applied to nipples of nursing mothers or to scarifications. A stem bark infusion is rubbed on to rheumatic and painful limbs, painful kidneys and to treat oedema. In Gabon beaten stem bark is taken as a mouth wash to treat toothache. In Congo and DR Congo the leaves, crushed together with the stem bark of Cola ballayi Cornu ex Hack., are applied to broken limbs as an embrocation to treat swellings. Young leaves are cut and cooked with fish and eaten to treat enlarged spleen. Leaf sap or stem bark latex, sometimes with banana or in palm wine, is taken to treat stomach-ache, gonorrhoea, intestinal worms, coughing fits and food poisoning. Bark scrapings are applied as an enema to treat malaria and backache. A maceration of the stem bark is applied as a wash to treat hernia and urinary infections. The twig or root bark latex mixed with palm oil is applied as a lotion to treat measles. A root decoction is drunk as an emetic. The ash from the stem bark or root bark mixed with palm oil is applied to kill lice. A bark extract is rubbed on the body as a mosquito repellent. Bark latex is applied to snakebites. A stem bark decoction is drunk as an emetic and antidote against Erythrophleum suaveolens (Guill. & Perr.) Brenan poisoning in ordeal by poison. Cows are given leaf sap with salt to increase milk production.
The wood is used as firewood and for charcoal making. The stems are used as poles for making huts and sometimes also in carpentry. In Gabon the wood is used for plywood production. In West Africa the twigs are used as chew sticks. In Benin, Gabon and Congo the beaten stem bark is used as soap for washing clothes.
A preliminary screening of the leaves and stem bark of Tetrorchidium didymostemon revealed the presence of saponins and traces of alkaloids.
The wood is pinkish, soft to moderately hard and perishable.
Dioecious, evergreen, glabrous liana, shrub or small tree up to 12 m tall, sometimes a medium-sized tree up to 25 m tall, with drooping branches; latex usually white, sometimes reddish or colourless; bark smooth or minutely fissured, brown; twigs slightly zigzag, prominently scarred at the nodes. Leaves alternate on flowering shoots, opposite on other branches; stipules small; petiole 0.5–1 cm long, channelled; blade obovate to elliptical-oblanceolate or elliptical, (4–)7–12(–17) cm × (2–)3–6(–8) cm, base cuneate, apex abruptly acuminate, margins entire or sometimes shallowly and remotely toothed, firmly papery, pinnately veined with 5–9 pairs of lateral veins. Inflorescence axillary to leaf-opposed, male inflorescence a densely flowered spike 2.5–8 cm long, female inflorescence a 3–5-flowered false umbel 1–1.5 cm long; peduncle 0.5–1 cm long. Flowers unisexual, 3-merous, petals absent; male flowers sessile, sepals broadly ovate, c. 0.7 mm long, minutely fringed, greenish yellow, stamens short; female flowers with pedicel 2–4 mm long, sepals triangular-ovate, c. 1 mm long, minutely fringed, greenish, disk glands petal-like, triangular-ovate, up to 1 mm long, yellowish green, ovary superior, almost globose, 1.5–2 mm in diameter, 3-celled, smooth, styles 3, forming a cap c. 1 mm in diameter. Fruit a 3-lobed capsule c. 5 mm × 6 mm, smooth, green becoming brownish green, 3-seeded. Seeds compressed ellipsoid, 4–5 mm × 3–4 mm, orange-red, pitted.
Other botanical information
Tetrorchidium comprises about 25 species, of which 5 occur in tropical Africa and the others in tropical America. Several other Tetrorchidium spp. are also used medicinally in Central Africa. In Congo bark latex of Tetrorchidium congolense J.Léonard, occurring in Gabon, Congo and DR Congo, is taken in palm wine to treat diarrhoea. Tetrorchidium oppositifolium (Pax) Pax & K.Hoffm. occurs in the forest area of West Africa, Cameroon and Gabon. In Liberia a bark infusion is taken as a febrifuge. In Gabon bark scrapings mixed with palm oil are massaged on painful areas caused by rheumatism. A bark infusion is used as eye drops to treat eye complaints.
Wood-anatomical description (IAWA hardwood codes):
Growth rings: 2: growth ring boundaries indistinct or absent. Vessels: 5: wood diffuse-porous; (12: solitary vessel outline angular); 13: simple perforation plates; 22: intervessel pits alternate; (23: shape of alternate pits polygonal); 27: intervessel pits large ( 10 μm); 30: vessel-ray pits with distinct borders; similar to intervessel pits in size and shape throughout the ray cell; 31: vessel-ray pits with much reduced borders to apparently simple: pits rounded or angular; 41: mean tangential diameter of vessel lumina 50–100 μm; 42: mean tangential diameter of vessel lumina 100–200 μm; 47: 5–20 vessels per square millimetre. Tracheids and fibres: 61: fibres with simple to minutely bordered pits; (65: septate fibres present); 66: non-septate fibres present; 68: fibres very thin-walled; 69: fibres thin- to thick-walled. Axial parenchyma: 76: axial parenchyma diffuse; 77: axial parenchyma diffuse-in-aggregates; 78: axial parenchyma scanty paratracheal; 93: eight (5–8) cells per parenchyma strand; 94: over eight cells per parenchyma strand. Rays: 97: ray width 1–3 cells; (100: rays with multiseriate portion(s) as wide as uniseriate portions); 108: body ray cells procumbent with over 4 rows of upright and/or square marginal cells; 116: 12 rays per mm. Mineral inclusions: (144: druses present); (145: druses in ray parenchyma cells); (148: druses in chambered cells).
(D. Louppe, P. Détienne & E.A. Wheeler)
Tetrorchidium didymostemon is common in secondary forest, at forest edges or along rivers, lakesides and swamps, from sea-level up to 1700 m altitude.
Propagation and planting
The seeds are dispersed by birds that feed on the fruits.
The leaves, stem bark and latex of Tetrorchidium didymostemon are harvested whenever the need arises.
Handling after harvest
The harvested parts are usually used fresh.
Genetic resources
Tetrorchidium didymostemon has a large distribution area and is common; therefore it is not threatened by genetic erosion.
Tetrorchidium didymostemon has many local medicinal uses, but virtually nothing is known concerning the chemical compounds or pharmacology of the plant parts and therefore more research is warranted.
Major references
• Burkill, H.M., 1994. The useful plants of West Tropical Africa. 2nd Edition. Volume 2, Families E–I. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 636 pp.
• CE-FAO, 1999. Données statistiques des produits forestiers non-ligneux du Cameroun. Rapport technique. Programme de partenariat CE-FAO (1998–2001), Rome, Italy. 36 pp.
• Keay, R.W.J., 1989. Trees of Nigeria. A revised version of Nigerian trees (1960, 1964) by R.W.J. Keay, C.F.A. Onochie and D.P. Stanfield. Clarendon Press, Oxford, United Kingdom. 476 pp.
• Latham, P., 2004. Useful plants of Bas-Congo province, Democratic Republic of the Congo. DFID, London, United Kingdom. 320 pp.
• Masiala, M.I., 2002. Ethnophytothérapies des Yombe de la réserve de biosphère de Luki Bas - Fleuve (R.D.C.). Rapport final UNESCO. 108 pp.
• Neuwinger, H.D., 2000. African traditional medicine: a dictionary of plant use and applications. Medpharm Scientific, Stuttgart, Germany. 589 pp.
• Radcliffe-Smith, A., 1987. Euphorbiaceae (part 1). In: Polhill, R.M. (Editor). Flora of Tropical East Africa. A.A. Balkema, Rotterdam, Netherlands. 407 pp.
• Raponda-Walker, A., 2005. Rites et croyances des peuples du Gabon. Deuxième édition révisée, Editions Raponda-Walker, Libreville, Gabon. 377 pp.
• Toirambe, B.B., 1989. Les plantes antipaludiques de Kisangani (Haut-Zaïre). Mémoire inédit, Faculté des Sciences, Université de Kisangani, Kisangani, DR Congo. 112 pp.
• Wome, B., 1985. Recherches ethnopharmacognosiques sur les plantes médicinales utilisées en médecine traditionnelle à Kisangani (Haut-Zaïre). PhD thesis, Faculty of Sciences, University of Brussels, Brussels, Belgium. 561 pp.
Other references
• Adjanohoun, E.J., Ahyi, A.M.R., Aké Assi, L., Baniakina, J., Chibon, P., Cusset, G., Doulou, V., Enzanza, A., Eymé, J., Goudoté, E., Keita, A., Mbemba, C., Mollet, J., Moutsamboté, J.-M., Mpati, J. & Sita, P. (Editors), 1988. Médecine traditionnelle et pharmacopée - Contribution aux études ethnobotaniques et floristiques en République Populaire du Congo. Agence de Coopération Culturelle et Technique, Paris, France. 606 pp.
• InsideWood, undated. [Internet] Accessed May 2007.
• Léonard, J., 1962. Euphorbiaceae. In: Robyns, W., Staner, P., Demaret, F., Germain, R., Gilbert, G., Hauman, L., Homès, M., Jurion, F., Lebrun, J., Vanden Abeele, M. & Boutique, R. (Editors). Flore du Congo belge et du Ruanda-Urundi. Spermatophytes. Volume 8, 1. Institut National pour l’Étude Agronomique du Congo belge, Brussels, Belgium. 214 pp.
• Noumi, E., 2004. Animal and plant poisons and their antidotes in Eseka and Mbalmayo regions, Centre Province, Cameroon. Journal of Ethnopharmacology 93: 231–241.
• Stäuble, N., 1986. Etude ethnobotanique des Euphorbiacées d’Afrique de l’Ouest. Journal of Ethnopharmacology 16: 23–103.
• Terashima, H. & Ichikawa, M., 2003. A comparative ethnobotany of the Mbuti and Efe hunter-gatherers in the Ituri forest, Democratic Republic of Congo. African Study Monographs 24(1–2): 1–168.
• Vivien, J. & Faure, J.J., 1988. Fruitiers sauvages du Cameroun. Fruits Paris 43(11): 657–676.
• Yamada, T., 1999. A report of the ethnobotany of the Nyindu in the eastern part of the former Zaire. African Study Monographs 20(1): 1–72.
Sources of illustration
• Aubréville, A., 1959. La flore forestière de la Côte d’Ivoire. Deuxième édition révisée. Tome deuxième. Publication No 15. Centre Technique Forestier Tropical, Nogent-sur-Marne, France. 341 pp.
B. Toirambe
Laboratoire de Biologie du bois et Xylarium, Musée Royal pour l’Afrique Centrale, Leuvensesteenweg 13, 3080 Tervuren, Belgium

G.H. Schmelzer
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
A. Gurib-Fakim
Faculty of Science, University of Mauritius, Réduit, Mauritius
Associate editors
C.H. Bosch
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
M.S.J. Simmonds
Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AB, United Kingdom
R. Arroo
Leicester School of Pharmacy, Natural Products Research, De Montfort University, The Gateway, Leicester LE1 9BH, United Kingdom
A. de Ruijter
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
General editors
R.H.M.J. Lemmens
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
L.P.A. Oyen
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
Photo editor
A. de Ruijter
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands

Correct citation of this article:
Toirambe, B., 2008. Tetrorchidium didymostemon (Baill.) Pax & K.Hoffm. In: Schmelzer, G.H. & Gurib-Fakim, A. (Editors). Prota 11(1): Medicinal plants/Plantes médicinales 1. [CD-Rom]. PROTA, Wageningen, Netherlands.
Distribution Map wild

1, branch with male inflorescences; 2, part of branch with female inflorescence; 3, fruit.
Redrawn and adapted by Iskak Syamsudin

tree habit


fruiting branch

wood in transverse section

wood in tangential section

wood in radial section