Carapa guianensis aka Crabwood

Carapa guianensis is a large tree in the mahogany family, Meliaceae. Its common names include andiroba and crab oil tree. It comes from tropical America, including parts of the Caribbean. Its range spans Central America and much of northern South America. It grows in lowland rainforests, within or below the canopy. It favours swamp edges, riverbanks, and plains that flood at times.

The tree reaches about 115 feet (35 metres) in cultivation. Some forest trees reach 180 feet (55 metres). PFAF gives a spread of about 66 feet (20 metres). The trunk grows straight and has a round cross-section. Most trunks measure 2–3 feet (0.6–0.9 metres) across. Buttresses or a swollen base help mark its form. Older trees tend to grow roots near the soil surface. Young trees first form a taproot. Reports differ on how long the tree keeps its leaves. Sources describe it as evergreen, partly evergreen, or deciduous. It bears male and female flowers on the same tree.

This tree suits warm, wet sites in the lowland tropics. Sources place it in climates with temperatures of 20–35°C. Rainfall in these areas exceeds 118 inches each year. It prefers moist or wet soil and tolerates brief floods. It accepts sand, loam, and clay. Its soil pH range extends from very acid to mildly alkaline. The tree tolerates some shade, but overhead sun drives faster growth. PFAF lists it for USDA zones 10–12. Fresh seeds sprout best, while drying reduces their chance of success. Sow them on moist soil or cover them lightly. Fresh seed can sprout in about three weeks.

People grow andiroba for timber, seed oil, and ornamental use. They also harvest trees from the wild. Its wood serves in furniture and containers. Seed oil supplies fuel for lamps and material for soap and candles. People also use the oil on skin and hair. It helps repel mosquitoes and several other biting pests. Planting schemes use the tree to help restore soil fertility. Seeds can contain as much as 70 percent oil.

Traditional medicine uses the bark, leaves, fruit rind, and oil. Reported uses include skin washes and treatments for fever and gut complaints. These records describe uses, not proof of safe or effective treatment. The bark contains tannins and a bitter alkaloid called carapine. Despite general entries stating no known hazards, PFAF warns against eating the oil. It can poison people when consumed in quantity. PFAF gives the plant an edibility score of zero.