Big leaf mahogany is native to the main land of Central and South America, from Mexico to Peru, Bolivia and Brazil. It is found in all forest types, from the edge of the pine savannah to the climax rainforest, but mostly in mixed hardwood forest belts, along river banks, on deep alluvial soils of considerable fertility. It occurs scattered or in small groups, but densities of more than 4-8 trees/ha are rarely encountered. S. macrophylla grows best on well-drained sites with medium to heavy soils. It is now cultivated in plantations in many parts of the tropics. In Kampala, Big leaf mahogany can be found along Jinja road among other places.

Very large tree, reaching a height of 30-40 m and a girth of 3-4 m; in favourable conditions it can reach 60 m high and 9 m girth. Trunk straight, cylindrical, with a buttressed base.

BARK: dark brown, rough, flaking off in small patches. Flaky bark has a sweet odor.

LEAVES: paripinnate, up to 60 cm long; leaflets 6-16, ovate, lanceolate, acuminate, slightly oblique, light green or reddish when young, dark green and shining when mature, up to 20 cm long, with 8-12 pale, secondary nerves.

FLOWERS:8 mm across, in narrow supra-axillary panicles about 8-13 cm long and fragrant; petals greenish-white, oblong, 4 mm long, rigidly pointed.

FRUIT: grey-browna woody capsule resembling a large inverted club, about 12.5 x 7.5 cm, erect.

An ornamental tree.

Agroforestry: used in reforestation projects and has proved to be suitable in areas not protected from grazing, used as a shade tree, for example, for cacao, coffee and young plantations of dipterocarps, when young, it can be used as an under-crop for teak (Tectona grandis), used in intercropping with crops like such as corn, beans, bananas, sweet potatoes and cassava, rushed fruit shells have been used as a potting medium (soil improver).

A gum is produced from cuts in the bark is marketed in both pure form and mixed with other gums.

The bark is used for dyeing and tanning leather.

An oil can be extracted from the seed kernels.

The wood is used in interior panelling, joinery work, turnery, plywood and heavy construction work, make sfurniture and hand tools. It is also suitable for precision woodwork such as models and patterns, instrument cases, clocks, printer's blocks and parts of musical instruments. 

Medicine: bark. http://tropical.theferns.info/viewtropical.php id=Swietenia+macrophylla