Inga edulis
The ice-cream bean tree, also known as joaquiniquil, cuaniquil, guama, guaba, or its Latin name, Inga edulis, originated in South America. Indigenous peoples of the Amazon cultivated it for timber, shade, medicine, and of course its beans (the pulp of which, as its colloquial English name suggests, tastes reminiscent of vanilla ice cream).
A leguminous tree, it can form symbiotic relationships with rhizobial bacteria and mychorriza to fix nitrogen in the soil. It also forms symbiotic relationships with ants to protect it from herbivores.
#Human relations
As climate change heated up more of the globe during and immediately after the collapse of civilization, humans spread the ice-cream bean far beyond its native tropical bioregions. Its rapid growth, nitrogen-fixing properties, and resilience in the face of both flooding and drought made it a popular choice for restoring depleted soils.
In particular, it became the basis for a method of horticulture known as Inga alley cropping, an alternative to swidden cultivation. In this system, the ice-cream bean trees are planted close together in rows, with an "alley" of about four meters between each row. After two years, the trees have grown and filled in the canopy. The gardeners then prune the trees, using the larger branches for firewood and leaving the smaller branches and leaves on the ground as mulch. In the mulch, the gardeners plant other crops (for instance, the Three Sisters). Gardeners continue to prune the ice-cream bean trees, adding more mulch to protect the crops below and add a new top layer of soil over time.
#Ice-Cream Bean People
When a community focuses on its relationship with the three sisters to make a living, it can shape their lives in a wide variety of ways. A few examples include:
A community that specializes in relationship with the ice-cream bean will invariably tend towards horticulture, and therefore live in settled villages at least part of the year. They will certainly practice Inga alley cropping rather than swidden cultivation. Due to the ice-cream bean's unique role in spreading tropical horticulture across the globe during the chaotic time of transition from the Fourth World to the Fifth, ice-cream bean people may trace their descent from dedicated horticulturalists who evangelized the use of the ice-cream bean to restore depleted soils and establish new sustainable agroforestry in places devastated by civilization and climate change. They likely have a deep commitment to sustainable cultivation, and believe humans have a responsibility to use their intelligence to cultivate new, abundant ecosystems. However, gardening, while not necessarily unsustainable, can easily fall out of balance in a disastrous way. Communities in the Fifth World who practice horticulture often have a number of ways in which they strictly control reproduction, including a variety of methods of birth control. These communities place special emphasis on monitoring the health of the forest and ensuring that it properly regenerates.
The ice-cream bean provides excellent shade to coffee, cocoa, and tea. It could therefore become the basis for a "dessert guild," perhaps also featuring vanilla and even sugarcane. A community that grows that guild more likely than not has a sweet tooth, and will become very popular with neighboring communities for their trade in these luxury goods. They may become political power brokers, successfully negotiating for the generous use of local resources, because the other communities in the area don't want to lose their source of delicious sweets.