Croton decaryi (PROTA)

Plant Resources of Tropical Africa Introduction

List of species

General importance
Geographic coverage Africa
Geographic coverage World
Medicinal

Croton decaryi Leandri

Protologue: Bull. Mus. natn. Hist. nat., Paris, sér. 2, 3: 370 (1931).

Family: Euphorbiaceae

Croton decaryi is endemic to south-western Madagascar.

The aromatic leafy branches are used as a mattress filler to repel insects, especially lice. A decoction of the aerial parts is taken to calm patients with paranoid psychosis.

Dry leaves of Croton decaryi contain about 0.3% essential oil, dry stems 0.2%. The essential oil of the leaves is rich in monoterpene and sesquiterpene hydrocarbons. Major components are β-caryophyllene (27%), α-pinene (21%), α-humulene (19%), β-pinene (7%) and caryophyllene oxide (5%). The essential oil of the dried stem contains mainly monoterpenes and oxygenated monoterpenes, and the major components are α -pinene (26%), borneol (13%), camphene (11%), β-pinene (7%), β-caryophyllene (9%) and caryophyllene oxide (6%).

Monoecious shrub up to 2 m tall; young twigs with short, reddish stellate hairs. Leaves opposite to whorled, simple, strongly scented; stipules small, persistent; petiole c. 1.5 cm long; blade ovate, c. 3 cm × 2 cm, base cordate, with 2 small, sessile glands, apex rounded, margins toothed, with small, cup-shaped glands in forks of veins, softly hairy on both sides, whitish beneath. Inflorescence a terminal raceme with male flowers at apex and 2–3 female flowers at base. Flowers unisexual, 5-merous, regular, white; sepals small, petals rudimentary; male flowers with short pedicel, stamens c. 15, free; female flowers with pedicel c. 2 cm long, ovary superior, rounded, 3-lobed, yellowish hairy, 3-celled, styles 3, several times 2-fid. Fruit an ovoid 3-lobed capsule, softly stellate hairy, 3-seeded.

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 decaryi.

Croton bathianus

The crushed stems of Croton bathianus Leandri are added to a fermented beverage and taken as a bitter tonic.

Croton crocodilorum

An infusion of the bitter bark of Croton crocodilorum Leandri is taken as a stimulant and aphrodisiac.

Croton perrieri

An infusion of the grated bark of Croton perrieri Leandri is taken to treat infectious diseases.

Croton decaryi occurs in open forest and on stream banks, at low altitudes.

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

Probably due to its essential oil, Croton decaryi is interesting for use as an insect repellent, but is likely to remain of minor, local importance only.

• 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.

• 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.

• 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.

• Ralaivao, H., 1993. Les maladies et les plantes utilisées dans le fivondronanna d’Ambilobe Andranomamy et Malaipaka. Thèse pour l’obtention du grade de Docteur en médecine (Diplôme d’Etat), Etablissement d’Enseignement Supérieur des Sciences de la Santé, Faculté de Médecine, Université d’Antananarivo, Madagascar. 107 pp.

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

Schmelzer, G.H., 2007. Croton decaryi 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.