Croton geayi (PROTA)

Plant Resources of Tropical Africa Introduction

List of species

General importance
Geographic coverage Africa
Geographic coverage World
Medicinal

Croton geayi Leandri

Protologue: Bull. Mus. natn. Hist. nat., Paris, sér. 2, 3: 368 (1931).

Family: Euphorbiaceae

Origin and geographic distribution

Croton geayi is endemic to south-western Madagascar.

Uses

An infusion of the aromatic leafy twigs is taken to treat fever, cough, asthma and constipation in newborn babies.

Properties

The dry aerial parts of Croton geayi contain about 0.3% essential oil. The essential oil contains mainly oxygenated monoterpenes, sesquiterpenes and oxygenated sesquiterpenes. Major components are 1,8-cineol (16%), β-carophyllene (15%), α -terpineol (14%), T-muurolol (7%), γ-cadinene (5%) and 4-terpineol (5%). Some diterpenes have been isolated from the wood: geanine, geaninine and derivatives.

Description

Monoecious, aromatic shrub up to 1.5 m tall; young twigs glabrous. Leaves whorled, simple and entire; stipules small; petiole 3–5 mm long; blade elliptical, c. 2 cm × 0.5 cm, base rounded, with 2 small, yellow glands, apex acute, short-hairy above, with silvery brown, shiny scales beneath. Inflorescence a terminal raceme, with many male flowers at apex and 1–2 female flowers at base. Flowers unisexual, 5-merous, regular; pedicel white to yellowish green; male flowers with small sepals and small petals, stamens c. 15, free; female flowers with small sepals, petals absent, ovary superior, globose, 3-lobed, silky hairy, 3-celled, styles 3, several times 2-fid. Fruit an ovoid 3-lobed capsule c. 7 mm long, covered with brown scales, 3-seeded. Seeds ovoid.

Other botanical information

Croton comprises about 1200 species and occurs throughout the warmer regions of the world. It is best represented in the Americas; about 65 species occur in continental Africa and about 125 in Madagascar. Almost 40 of the species from Madagascar are used in medicine, and several of them resemble morphologically Croton geayi.

Croton adabolavensis

An infusion of the leafy twigs of Croton adabolavensis Leandri is taken to treat dysentery.

Croton androiensis and elaeagni

The aromatic leafy branches of Croton androiensis (Leandri) Leandri and Croton elaeagni Baill. are used as a mattress filler to repel insects, especially lice. A root bark decoction of Croton androiensis is externally applied for its cicatrizing effect and to treat caries. A bark decoction of Croton elaeagni is taken to treat a cough.

Croton jennyanus

A decoction of the aerial parts of Croton jennyanus Gris. ex Baill. is taken to calm patients with delirium, paralysis or Parkinson’s disease. The seeds are taken as a strong purgative, but are considered dangerous.

Ecology

Croton geayi occurs in rocky localities, on calcareous or sandy soil, at 100–1400 m altitude. It prefers sunny localities.

Genetic resources

There are no signs that Croton geayi is threatened by genetic erosion.

Prospects

Croton geayi has some interesting local medicinal uses, but more information is needed to evaluate its potential.

Major references

• Boiteau, P., Boiteau, M. & Allorge-Boiteau, L., 1999. Dictionnaire des noms malgaches de végétaux. 4 Volumes + Index des noms scientifiques avec leurs équivalents malgaches. Editions Alzieu, Grenoble, France.

• CNRE (Centre National de Recherche sur l’Environnement) & ONE (Office National pour l’Environnement), 2001. Valorisation des filières potentielles en matière de biodiversité : les plantes médicinales dans la région de la forêt de Mikea. Rapport final des travaux de recherche dans la région de Mikea, Tuléar, Antananarivo, Madagascar. 105 pp.

• Govaerts, R., Frodin, D.G. & Radcliffe-Smith, A., 2000. World checklist and bibliography of Euphorbiaceae (with Pandaceae). Royal Botanic Gardens, Kew, Richmond, United Kingdom. 1620 pp.

• Leandri, J., 1939. Les Croton de Madagascar et des îles voisines. Annales de l’Institut Botanique-Géologique Colonial de Marseille 7(1). 100 pp.

• Radulovic, N., Mananjarasoa, E., Harinantenaina, L. & Yoshinori, A., 2006. Essential oil composition of four Croton species from Madagascar and their chemotaxonomy. Biochemical Systematics and Ecology 34(8): 648–653.

Other references

• Coode, M.J.E., 1982. Euphorbiacées. In: Bosser, J., Cadet, T., Guého, J. & Marais, W. (Editors). Flore des Mascareignes. Familles 153–160. The Sugar Industry Research Institute, Mauritius, l’Office de la Recherche Scientifique Outre-Mer, Paris, France & Royal Botanic Gardens, Kew, Richmond, United Kingdom. 117 pp.

• Missouri Botanical Garden, undated. VAST (VAScular Tropicos) nomenclatural database. [Internet] http://mobot.mobot.org/W3T/Search/vast.html. December 2006.

• Palazzino, G., Federici, E., Rasoanaivo, P., Galeffi, C. & Delle Monache, F., 1997. Research on African medicinal plants 37. 3,4-seco diterpenes of Croton geayi. Gazzetta Chimica Italiana 127(6): 311–314.

• Ralantonirina, D., 1993. Aperçu sur les plantes médicinales dans le sud de Madagascar : étude faite sur les adultes dans le périmètre de la réserve spéciale de Beza - Mahafaly. Thèse pour l’obtention du grade de Docteur en médecine, Etablissement d’Enseignement Supérieur des Sciences de la Santé, Faculté de Médecine, Université d’Antananarivo, Madagascar. 95 pp.

• Rasoanaivo, P., Ratsimamanga-Urverg, S., Ramanitrahasimbolo, D., Rafatro, H. & Rakoto-Ratsimamanga, A., 1999. Criblage d’extraits de plantes de Madagascar pour recherche d’activité antipaludique et d’effet potentialisateur de la chloroquine. Journal of Ethnopharmacology 64: 117–126.

• Razafiarison, C., 1993. Aperçu sur les plantes médicinales dans le sud de Madagascar : étude faite sur les enfants dans le périmètre de la réserve spéciale de Beza - Mahafaly. Thèse pour l’obtention du grade de Docteur en Médecine, Etablissement d’Enseignement Supérieur des Sciences de la Santé, Faculté de Médecine, Université d’Antananarivo, Madagascar. 93 pp.

Author(s)

• G.H. Schmelzer, PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands

Correct citation of this article

Schmelzer, G.H., 2007. Croton geayi Leandri. In: Schmelzer, G.H. & Gurib-Fakim, A. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands. Accessed 3 April 2025.

• See the Prota4U database.