Within the Inga genus there are around 300 species, most of them native and growing in the Amazon forest region although some species are also found in Mexico, Greater and Lesser Antilles and other countries in South America, being an exclusively neotropical genus. The trees are usually found by river and lake edges because their seeds are carried there by floods.
Fruit of an Inga-species. Trees can reach up to 15 metres and they are widely used for producing shade over coffee plants. The plant benefits from well drained soil. The flowers are white with some green and the tree can produce fruits almost all year long.
The seeds are covered with sweet white powder. The pulp covering the seeds is lightly fibrous and sweet, and rich in minerals; it is edible in the raw state. The tree's name originates from the Tupi word in-gá meaning "soaked", due to the fruit powder consistency. The tree usually blossoms twice a year.
All Inga species produce their seeds in "bean-like" pods and some can reach up to 1 m long, in general the pods are 10–30 cm long.
Inga species are also commonly used as shade trees for coffee, cocoa, and tea.
Agroforestry:
Commonly planted as a shade tree in coffee and cacao plantations, since it is fast-growing, fixes atmospheric nitrogen, has a well spreading crown and produces large quantities of leaves which cover the ground and add considerable quantities of organic matter to the soil. In trial experiments on cultivated slopes, a mulch from this tree reduced soil erosion to levels almost equal to those in secondary forests. The leaf litter is high in nitrogen, lignins and polyphenols. It is slow to decompose, but provides a long-term build up of organic nitrogen and effective weed control. Weed biomass decreased considerably in all agroforestry trials with this species, much more than with other leguminous species. Existing trials are too new to ascertain whether the species can maintain or improve soil fertility on acid sites in the long term, but results so far are promising.
Other Uses: The heartwood is light brown with dark stripes; the sapwood is pale yellow or almost white. The texture is coarse; the grain straight to interlocked; lustre is medium; there is no distinctive taste or aroma. The wood is not very heavy; hard to moderately hard. It is said to be very durable, even in water, though another report says it has low durability and is susceptible to blue stain. It is easy to cut, saws slightly woolly and is liable to split in drying. It is used for making packing cases, and especially for making piles. The wood is used for fuel, but ALL wood is used for cooking by about 73% of Guatemalans. A popular source of firewood, the wood has a high calorific value and burns with little smoke.
Distribution and ecology
Chaya is easy to grow, a tender perennial in the US, and suffers little insect damage. It is tolerant of heavy rain and has some drought tolerance. Propagation is normally by woody stem cuttings about 6-12 inches long, as seeds are produced only rarely. Early growth is slow as roots are slow to develop on the cuttings, so leaves are not harvested until the second year. Chaya leaves can be harvested continuously as long as no more than 50% of the leaves are removed from the plant, which guarantees healthy new plant growth.
