Lemongrass
Lemongrass, a tropical grass, originated in Malesia but now grows widely across the Fifth World.
#Human usage
People use lemongrass as an herb in cooking, particularly to season poultry and seafood. They also brew it in a tea, either by itself or as flavoring in another kind of tea. Aside from cooking, people of the Fifth World will often weave the dried leaves into walls and sleeping mats for its pleasant scent, anti-fungal properties, and insect deterrence.
In many places, people believe lemongrass to have medicinal value, but exactly which ailments it treats varies by culture. Most generally agree, however, that it has calming properties and encourages overall health.
#Specialization
A community that specializes in relationship with lemongrass will often tend towards horticulture, and therefore probably live in settled villages. Often these communities practice slash-and-burn agriculture, growing different guilds of plants at different stages and moving around the jungle in a regular cycle. Because of the ease of growing lemongrass, its tolerance of partial shade, and its mosquito-deterring properties, such communities will often plant them around the edge of the village. Lemongrass also finds a home in traditional "banana circles" along with with banana, cassava, sweet potato, and taro.
Communities that practice beekeeping also find use in lemongrass, as it attracts bee swarms. These communities will plant lemongrass near empty hives to which they want to attract bees.
Because lemongrass grows so easily and widely, however, not all communities that specialize in relationship with it will necessarily live in settled villages. More nomadic communities might have a close relationship with it if they follow semi-feral herds of animals that enjoy eating lemongrass or appreciate the way it deters flies.