Prota 16: Fibres/Plantes à fibres
Fl. Réunion: 312 (1895).
Sterculiaceae (APG: Malvaceae)
Mahot, mahot blanc, grand mahot blanc, bois de senteur (Fr).
Origin and geographic distribution
Dombeya pilosa is endemic to Réunion.
The bark fibre is used for tying, and sometimes trees are found with strips of bark removed. The wood is not very important, but can be used in construction.
The wood is lightweight and not durable. Flowering trees have ornamental value, especially the male ones, which have larger flowers that fall before withering and turning brown. Methanolic extracts of the leaf and stem have shown some radical scavenging and antioxidant activity.
Dioecious, small to medium-sized tree up to 20 m tall; bole up to 70 cm in diameter; outer bark grey, more or less smooth; all growing organs sticky and covered with a white indumentum of stellate and simple hairs 2–3 mm long. Leaves alternate, simple; stipules triangular, 1.5 mm long, sparsely hairy, covered with numerous glands with a sticky exudate, fairly persistent; petiole 5–12 cm long, often with simple hairs, rarely almost glabrous; blade broadly ovate, 6–12(–18) cm × 5–10(–13) cm, base deeply cordate, apex long-acuminate, margin toothed, both surfaces sparsely covered with stellate and simple hairs, palmately veined. Inflorescence an axillary, dense, umbelliform cyme, often completely spherical, 4–9 cm in diameter, the female ones smaller than the male, up to 50-flowered; peduncle 7–16(–19) cm long, hairy, sometimes with 2(–4) large bracts at the apex. Flowers unisexual, regular, 5-merous; pedicel slender, 1–2 cm long, hairy, glandular; epicalyx bracts 3, triangular or ovate, 10–13 mm long, with a long acumen, sparsely covered with simple hairs, caducous; sepals valvate, petals white or pale pink; male flowers c. 2 cm in diameter, sepals 6–8 mm long, apiculate, hairy outside, glabrous inside, petals 9–13 mm long, androecium 9–11 mm long, staminal tube 1 mm long, gynoecium sterile and 5–6 mm long; female flowers 1–1.5 cm in diameter, sepals c. 5 mm long, petals 6–7 mm long, androecium sterile and 3–5 mm long, staminal tube 0.5–1.5 mm long, ovary superior, whitish hairy, 5-celled, style short. Fruit a capsule, reddish, 5–10-seeded.
Flowering is mainly in February–March, but it sometimes occurs earlier and may extend into July.
Dombeya comprises about 200 species, mainly distributed in Madagascar, with about 20 species in mainland Africa and 14 in the Mascarenes. Revisions of the genus have been carried out for mainland Africa and the Mascarenes, but not for Madagascar, and the number of species described for Madagascar is possibly too high.
Dombeya umbellata Cav. (‘mahot blanc’, ‘mahot des hauts’) is a small tree up to 15 m tall, endemic to Réunion. Its bark has been used for making rope and rough tissue, and the lightweight wood for making rafts. The species has become rare, however.
Dombeya reclinata Cordem. (‘mahot rouge’, ‘bois de senteur rouge’) is a small tree up to 10 m tall, endemic to Réunion. Its fibrous bark is used for tying faggots, and its white and lightweight wood for cabinet work.
Dombeya pilosa occurs fairly commonly in humid forest and other moist locations at (500–)1000–1500(–1900) m altitude.
Genetic resources and breeding
Dombeya pilosa is fairly common in Réunion, but does not occur elsewhere. It hybridizes with Dombeya ficulnea Baillon.
Dombeya pilosa is a useful local source of tying material, but its importance is unlikely to increase.
• Association Flore Réunion, 2001. Encyclopédie on line de la flore de la Réunion. [Internet] http://www.flore reunion.com/frame.html. Accessed October 2009.
• Chan Ng Yok, H., 2009. La flore réunionaise. [Internet] http://www.liledelareunion.com/ Fr/Flore/index.htm. Accessed October 2009.
• Friedmann, F., 1987. Sterculiacées. In: Bosser, J., Cadet, T., Guého, J. & Marais, W. (Editors). Flore des Mascareignes. Familles 51–62. The Sugar Industry Research Institute, Mauritius, l’Office de la Recherche Scientifique Outre-Mer, Paris, France & Royal Botanic Gardens, Kew, Richmond, United Kingdom. 50 pp.
• Medina, J.C., 1959. Plantas fibrosas da flora mundial. Instituto Agronômico Campinas, Sao Paulo, Brazil. 913 pp.
• Poullain, C., Girard-Valenciennes, E. & Smadja, J., 2004. Plants from Reunion island: evaluation of their free radical scavenging and antioxidant activities. Journal of Ethnopharmacology 95: 19–26.
• Seyani, J.H., 1991. The genus Dombeya (Sterculiaceae) in continental Africa. Opera Botanica Belgica 2. National Botanic Garden of Belgium, Meise, Belgium. 186 pp.
Correct citation of this article:
Brink, M., 2010. Dombeya pilosa Cordem. In: Brink, M. & Achigan-Dako, E.G. (Editors). Prota 16: Fibres/Plantes à fibres. [CD-Rom]. PROTA, Wageningen, Netherlands.