Couma macrocarpa

Couma macrocarpa is an evergreen tree from tropical America. Its range spans Central America and northern South America. It belongs to the Apocynaceae family. Common names include sorva, barca, and milk tree. It grows in humid forests near sea level. It also occurs in cleared pasture and on well-drained Amazon uplands. Sources describe it as a tree of mature rainforest.

Garden descriptions give a height and spread of 82 feet [25 metres]. Forest accounts give heights of 39–92 feet [12–28 metres]. Exceptional trees reach 131 feet [40 metres]. The trunk can reach about 3.3 feet [1 metre] across. Thick, dark bark covers the trunk. The oval leaves grow in groups of three. Its flowers are small. Round, yellow-green fruit reaches about 0.2 feet [0.06 metres] across. Each fruit holds a few seeds within soft pulp.

This tree needs the warmth of the humid lowland tropics. Plants For A Future lists USDA zones 10–12. It grows at a moderate rate and prefers shade. The same source reports growth in partial shade or full sun. It needs moist soil with good drainage. Suitable soils include sand, loam, and clay. It tolerates mildly acid, neutral, and mildly alkaline soil. Seeds lose their ability to sprout soon after harvest. Sow ripe seed promptly in a shaded bed or container. Reported germination takes 25–35 days, with success above 70 percent.

People eat the fruit raw and sell it in local markets. Its sweet, juicy pulp has a very sticky texture. Cuts in the bark release a sweet, creamy latex. People drink this latex and use it to make chewing gum. An infusion of the leaves also serves as a drink. These food uses do not establish safety for every use. Plants For A Future warns of skin irritation or allergic reactions. Useful Tropical Plants lists no known hazards, so the accounts differ.

The tree also supplies wood and latex for practical uses. Boiling the latex produces material used to seal canoes. Other reported uses include furniture, containers, and insulation. Its food and material uses suit tropical food forests. Sources also describe coppice management, which involves repeated cutting and regrowth. Traditional medicine uses stem latex for amoebiasis, including amoebic dysentery. This records a reported use, not proof of treatment benefit.