PROTA homepage Prota 11(1): Medicinal plants/Plantes médicinales 1
Record display

Senna didymobotrya (Fresen.) H.S.Irwin & Barneby

Mem. New York Bot. Gard. 35: 467 (1982).
Caesalpiniaceae (Leguminosae - Caesalpinioideae)
Chromosome number
2n = 28
Cassia didymobotrya Fresen. (1839), Cassia nairobensis L.H.Bailey (1941).
Vernacular names
Candle bush, peanut-butter cassia, popcorn senna, wild senna, candelabra tree (En). Séné africain (Fr). Mwinu (Sw).
Origin and geographic distribution
Senna didymobotrya is native to tropical Africa where it is found from Congo east to Ethiopia and south to Namibia, Zimbabwe and Mozambique. It has been introduced as an ornamental plant into many tropical countries including the Comoros, Madagascar, Mauritius and South Africa. It was originally introduced into tropical Asia and America as a fodder, green manure and cover crop, but is now mainly cultivated as an ornamental.
Senna didymobotrya is widely used as a medicinal plant, especially in East Africa, where a decoction or infusion from the leaves, stems and roots is drunk as a laxative and purgative for the treatment of abdominal pains, while in large quantities it is taken as an emetic. In Uganda, Rwanda and Burundi it is also taken to expel intestinal worms and to treat ringworm. The concoction may make the patient weak and if this happens the patient should drink milk. When treating children, young leaves are cooked in banana leaves and given orally. In Kenya and Uganda an infusion made from the roots is drunk to treat diarrhoea.
In DR Congo, Rwanda, Burundi, Kenya, Uganda and Tanzania a root decoction is drunk for the treatment of malaria, other fevers and jaundice. The powder of the root or leaf mixed in water or a decoction of the fresh parts is taken to treat abscesses of the skeletal muscles and venereal diseases. The plant is also indicated for the treatment of fungal and bacterial infections, hypertension, haemorrhoids, sickle cell anaemia, and a range of women’s diseases, such as inflammation of the fallopian tubes, fibroids and backache, to stimulate lactation, and to induce uterine contractions and abortion.
Senna didymobotrya, like other Senna species, is poisonous. Decoctions from all plant parts can cause violent vomiting and diarrhoea and may be fatal. It is recommended that pregnant women and children take a small dose. The leaves and roots are also used as fish poison.
Senna didymobotrya is also widely used for the treatment of livestock diseases. A decoction made from the leaves, either alone or in mixtures, is used to treat external parasites, e.g. ticks. In Kenya the leaves and young stems are pounded to a pulp and applied to the skin to treat skin diseases. The leaf sap in water is given to drink to treat diarrhoea, dysentery, and taken as a diuretic, laxative, and emetic. A decoction made from the roots is used as an antidote for poisoning, to expel a retained placenta, and to treat East Coast fever and blackleg.
The ash of burnt twigs is used to coat the inside of gourds that are to be used for storing milk, as it is said to improve digestibility and palatability. The milk can be kept in them for over a year.
The wood is used for making handicrafts, and is also used as firewood. The leaves are used as mulch or green manure. Senna didymobotrya is sometimes planted as a shade tree in tea plantations. Flowers, bark, leaves and pods can be used as a colorant for fibres and give a wide range of colours (yellow, orange, red). The bark is used in leather making for dehairing and tanning. The leaves are used to ripen bananas by wrapping them around the bunch. The hot ashes are used to clean beer vessels. Senna didymobotrya is widely grown as an ornamental plant.
A number of anthraquinone derivatives have been isolated from the leaves and pods, e.g. emodin, chrysophanol, physcion and knipholone. Other compounds isolated from the leaves are aloe-emodin, rhein and small quantities of dianthrone emodin, dianthrone aloe-emodin, sennoside B, C and D, catechinic tannins, flavonoids and aloe-emodin B-glucoside. The seed contains 4% oil, 24% protein and 6% ash.
The anthraquinone derivatives are little resorbed in the small intestine but once in the colon, they are hydrolyzed by the bacterial flora and the anthraquinones formed are reduced to form the active anthrones, which are responsible for the laxative activity as they stimulate peristalsis. Anthraquinones such as emodin also inhibit ion transport across colon cells, contributing to the laxative effect. Anthraquinones exhibit other biological effects including diuresis, vasorelaxation, and induction of muscular contractions, antioxidant properties as well as antibacterial and antifungal activities. Emodin is known to be a feeding deterrent against a wide range of organisms.
Methanolic plant extracts reduced contractions induced by acetylcholine in isolated guinea pig trachea rings. This decrease was more than half of the relaxation induced by theophylline, a standard drug used in therapy for respiratory diseases. This property may be important for bronchodilatation in asthma treatment. The root and stem bark extracts inhibited growth of Giardia lamblia in in-vitro tests but were not lethal to this protozoan parasite that causes infection of the gastrointestinal tract.
The bioactivity of the plant against malaria is low, although it is fever-suppressing.
The smell of Senna didymobotrya, especially when in flower or when bruised, has been described as ‘mice’, ‘wet dogs’, ‘peanut butter’ or ‘burnt popcorn’, and bees are repelled by the smell.
Adulterations and substitutes
As a purgative Senna didymobotrya is often substituted for other Senna species and by Cassia and Aloe species.
Deciduous shrub or small tree up to 4.5(–9) m tall. Leaves arranged spirally, paripinnately compound with 8–18 pairs of leaflets; stipules broadly ovate-cordate, 1–2.5 cm × c. 1 cm, acuminate, persistent; petiole 1–8 cm long; leaflets oblong-elliptical, 2–6 cm × 0.5–2.5 cm, mostly rounded to obtuse at apex, mucronate, shortly hairy on both sides. Inflorescence an erect, axillary raceme 10–50 cm long, 20–30-flowered; bracts 1–2.5 cm long. Flowers bisexual, zygomorphic, 5-merous; sepals oblong-obovate, up to 1.5 cm long; petals unequal, oblong to obovate, 1.5–3 cm long, yellow; stamens 10, the 2 lower ones largest and fertile, 8 sterile; ovary superior, woolly, recurved, style slender, bent. Fruit a flattened, oblong pod 8–12 cm × 1.5–2.5 cm, transversely partitioned, dehiscent by 2 valves, 9–16-seeded. Seeds oblong, compressed, c. 8 mm × 4–5 mm, with a distinct areole on each face.
Other botanical information
Until the early 1980s, Cassia was considered a very large genus of about 550 species, but was then split into 3 genera: Cassia s.s. with about 30 species, Chamaecrista with about 250 species and Senna with about 270 species. Senna is very similar to Cassia, but is distinguished from it by the possession of 3 adaxial stamens which are short and straight, and the pedicels which have no bracteoles. The hairiness of Senna didymobotrya varies a good deal in length and density, and the bracts and stipules are variable in size. However, there seems no reason for recognizing subspecific taxa.
Growth and development
Senna didymobotrya flowers profusely twice a year in the tropics. It is a cross-fertilizer, but also self-compatible. Reports on nodulation are contradictory. When grown as a fallow crop, it appeared to enrich the topsoil with considerable amounts of nitrogen, but it was not clear where this came from. Senna didymobotrya stimulates the germination of witchweed (Striga) seeds although it is not a host. When incorporated in the rotation it can effectively decrease the infestation.
Senna didymobotrya is common in deciduous bushland, along lake shores, streams, rivers and other damp localities, in grassland and woodland, from sea-level up to 2500 m altitude. Sometimes it is found in old plantations and in hedges near buildings. In South Africa it has become invasive in grassland, coastal scrub, woodland, roadsides, wasteland and on river banks. It tolerates light frost.
Propagation and planting
Senna didymobotrya is propagated by seed and by cuttings. Seed germinates easily, but requires soaking in water for 24 hours because it exhibits some dormancy due to its hard seed coat. Dormancy can also be overcome by mechanical scarification and immersion in concentrated sulphuric acid or boiling water. Experiments with treated seed gave 75–85% germination, but the germination rate of untreated seeds is 15–20%. The seeds can germinate both in light and dark conditions and over a wide range of temperatures; however, the optimum germination temperature is 20–25°C and the germination rate is very low at 10°C.
Seeds can be dried without damage to moisture contents that are much lower than normally achieved in nature. Over a wide range of storage environments, their longevity increases with reductions in both moisture content and temperature. The weight of 1000 air-dry seeds is 36–75 g.
Senna didymobotrya is a good shade tree in tea in areas where Erythrina spp. are unsuitable. As such it is spaced at about 5 m × 5 m. Young stems are tender and should be staked.
Diseases and pests
Senna didymobotrya is hardly attacked by pests and diseases. It is a host of coffee mealy bug (Planococcus kenyae) that affects a wide range of crops.
Senna didymobotrya can be lopped for green manure several times per year, preferably when flowering, as at this stage nutrient contents of the leaves is highest.
The fresh leafy branches of Senna didymobotrya contain about 0.7% of N. A typical cut of 5 t/ha thus yields about 35 kg N.
Genetic resources
There is a small number of accessions of Senna didymobotrya in germplasm collections. As it is widespread, the species is not threatened by genetic erosion.
The pharmacological benefits of using Senna didymobotrya as a crude herbal medicine are outweighed by its potential toxicity. However, herbal extracts prepared under carefully controlled manufacturing settings have potential. The use as a green manure, cover crop and shade tree has never been important in Africa, but could increase. Its ability to induce germination of Striga seeds makes it a potential trap crop for inclusion in rotation with grain crops.
Major references
• Alemayehu, G., Hailu, A. & Abegaz, B.M., 1996. Bianthraquinones from Senna didymobotrya. Phytochemistry 42(5): 1423–1425.
• Brenan, J.P.M., 1967. Leguminosae, subfamily Caesalpinioideae. In: Milne-Redhead, E. & Polhill, R.M. (Editors). Flora of Tropical East Africa. Crown Agents for Oversea Governments and Administrations, London, United Kingdom. 230 pp.
• Gacheru, E. & Rao, M.R., 2005. The potential of planted shrub fallows to combat Striga infestation on maize. International Journal of Pest Management 51(2): 91–100.
• Izhaki, I., 2002. Emodin: a secondary metabolite with multiple ecological functions in higher plants. New Phytologist 155: 205–217.
• Kamatenesi-Mugisha, M., 2004. Medicinal plants used in reproductive health care in Western Uganda: documentation, phytochemical and bioactivity evaluation. PhD thesis, Makerere University, Kampala, Uganda. 228 pp.
• Katende, A.B., Birnie, A. & Tengnäs, B., 1995. Useful trees and shrubs for Uganda: identification, propagation and management for agricultural and pastoral communities. Technical Handbook 10. Regional Soil Conservation Unit, Nairobi, Kenya. 710 pp.
• Neuwinger, H.D., 2000. African traditional medicine: a dictionary of plant use and applications. Medpharm Scientific, Stuttgart, Germany. 589 pp.
• Okello-Onen, J., Kerwegi, S.A., Olila, D., Ssekitto, C.M.B. & Osinde, C., 2004. Participatory evaluation and improvement of ethno-veterinary practices for tick control in Lango and Teso farming system. Final Technical Report. LIRI, Tororo, Uganda. 20 pp.
• Sunarno, B., 1997. Senna didymobotrya (Fresenius) Irwin & Barneby. In: Faridah Hanum, I. & van der Maesen, L.J.G. (Editors). Plant Resources of South-East Asia No 11. Auxiliary plants. Backhuys Publishers, Leiden, Netherlands. pp. 229–231.
• World Agroforestry Centre, undated. Agroforestree Database. [Internet] World Agroforestry Centre (ICRAF), Nairobi, Kenya. Sites/TreeDBS/ aft.asp. Accessed July 2006
Other references
• den Biggelaar, C. & Mureithi, W., 2000. Using tree species to treat milk for palatability and preservation. Intermediate Technology Food Chain 26: 6–7.
• Geissler, P.W., Harris, S.A., Prince, R.J., Olsen, A., Achieng’ Odhiambo, R., Oketch-Rabah, H., Madiega, P.A., Andersen, A. & Mølgaard, P., 2002. Medicinal plants used by Luo mothers and children in Bondo district, Kenya. Journal of Ethnopharmacology 83: 39–54.
• Gessler, M.C., Msuya, D.E., Nkunya, M.H.H., Mwasumbi, L.B., Schär, A., Heinrich, M. & Tanner, M., 1995. Traditional healers in Tanzania: the treatment of malaria with plant remedies. Journal of Ethnopharmacology 48: 131–144.
• Hedberg, I., Hedberg, O., Madati, P.J., Mshigeni, K.E., Mshiu, E.N. & Samuelsson, G., 1982. Inventory of plants used in traditional medicine in Tanzania. I. Plants of the families Acanthaceae-Cucurbitaceae. Journal of Ethnopharmacology 6(1): 29–60.
• Hindmarsh, L., 1982. A notebook for Kenyan dyers. National Museum of Kenya, Nairobi, Kenya. 65 pp.
• Johns, T., Faubert, G.M., Kokwaro, J.O., Mahunnah, R.L.A. & Kimanani, E.K., 1995. Anti-giardial activity of gastrointestinal remedies of the Luo of East Africa. Journal of Ethnopharmacology 46: 17–23.
• Kasonia, K., 1995. Screening préliminaire d’extraits de plantes utilisées dans les maladies respiratoires au Kivu (Zaïre) sur trachée isolée de cobaye. Belgian Journal of Botany 128(2): 165–175.
• Kokwaro, J.O., 1993. Medicinal plants of East Africa. 2nd Edition. Kenya Literature Bureau, Nairobi, Kenya. 401 pp.
• Lindsay, R.S. & Hepper, F.N., 1978. Medicinal plants of Marakwet, Kenya. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 49 pp.
• Masinde, P.S., 1996., 1996. Medicinal plants of the Marachi people of Kenya. In: van der Maesen, L.J.G., van der Burgt, X.M. & van Medenbach de Rooy, J.M. (Editors). The biodiversity of African plants. Proceedings of the 14th AETFAT Congress, 22–27 August 1994, Wageningen, Netherlands. Kluwer Academic Publishers, Dordrecht, Netherlands. pp. 747–753.
• Minja, M.M.J., 1994. Medicinal plants used in promotion of animal health in Tanzania. In: Kasonia, K., Ansay, M., Baerts, M. & Lehmann, J. (Editors). Métissages en santé animale de Madagascar à Haïti. Actes d’un séminaire, Ouagadougou, Burkina Faso, 1993. Presses Universitaires de Namur, Namur, Belgium. pp. 335–364.
• Muregi, F.W., Chhabra, S.C., Njagi, E.N.M., Lang’at Thoruwa, C.C., Njue, W.M., Orago, A.S.S., Omar, S.A. & Ndiege, I.O., 2004. Anti-plasmodial activity of some Kenyan medicinal plant extracts singly and in combination with chloroquine. Phytotherapy Research 18(5): 379–384.
• Murengezi, I., 1993. Etude de l’activité antibacterienne de quelques plantes utilisées en médecine traditionnelle rwandaise. Revue de Médecines et Pharmacopées Africaines 7(1): 3–10.
• Rambuda, T.D. & Johnson, S.D., 2004. Breeding systems of invasive alien plants in South Africa: does Baker’s rule apply? Diversity and Distributions 10: 409–416.
• Schlage, C., Mabula, C., Mahunnah, R.L.A. & Heinrich, M., 2000. Medicinal plants of the Washambaa (Tanzania): documentation and ethnopharmacological evaluation. Plant Biology 2: 83–92.
• Tabuti, J.R.S., Lye, K.A. & Dhillion, S.S., 2003. Traditional herbal drugs of Bulamogi, Uganda: plants, use and administration. Journal of Ethnopharmacology 88: 19–44.
• Teketay, D., 1996. The effect of different pre-sowing seed treatments, temperature and light on the germination of five Senna species from Ethiopia. New Forests 11(2): 155–171.
• Thulin, M., 1989. Fabaceae (Leguminosae). In: Hedberg, I. & Edwards, S. (Editors). Flora of Ethiopia. Volume 3. Pittosporaceae to Araliaceae. The National Herbarium, Addis Ababa University, Addis Ababa, Ethiopia and Department of Systematic Botany, Uppsala University, Uppsala, Sweden. pp. 49–251.
• Van Puyvelde, L., 1988. Contribution to the study of Rwandese medicinal plants. PhD thesis, Leiden, Netherlands. 155 pp.
Sources of illustration
• Sunarno, B., 1997. Senna didymobotrya (Fresenius) Irwin & Barneby. In: Faridah Hanum, I. & van der Maesen, L.J.G. (Editors). Plant Resources of South-East Asia No 11. Auxiliary plants. Backhuys Publishers, Leiden, Netherlands. pp. 229–231.
J.R.S. Tabuti
Department of Botany, Makerere University, P.O. Box 7062, Kampala, Uganda

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:
Tabuti, J.R.S., 2007. Senna didymobotrya (Fresen.) H.S.Irwin & Barneby. In: Schmelzer, G.H. & Gurib-Fakim, A. (Editors). Prota 11(1): Medicinal plants/Plantes médicinales 1. [CD-Rom]. PROTA, Wageningen, Netherlands.
Distribution Map wild and planted

1, flowering and fruiting branch; 2, stipule; 3, side view of flower; 4, flower in longitudinal section; 5, seed.
Source: PROSEA

flowering plant habit

flowering and fruiting plant

leafy branch with inflorescences