Toxicologists say that black nightshade, Solanum nigrum, contains several glycoalkaloids, which depress the central nervous system.
A literature search revealed that the Rappanhannock Indians once used the leaves of the black nightshade to treat insomnia.
While Duchon's apparent reaction to the plant -- and the Hmong's apparent lack of a reaction -- remains unexplained, she advises against trying black nightshade as a spinach substitute or sleeping pill.
It turns out the Hmong aren't the only people to favor black nightshade at dinnertime.
At last year's Society of Ethnobiology meeting, Johns reported that the Luo eat black nightshade to combat gastrointestinal ills.
Black nightshade is the most known traditional vegetable in the country.
The two types of black nightshade can be sown directly in the farm or in a nursery before being transplanted in a seedbed.
Some farmers prefer sun-drying the leaves so as to increase the shelf life of the black nightshade vegetable.
Unlike the transplanted black nightshade, the ones planted directly in the bed are usually harvested by uprooting.The plants could be attacked by Tuta absoluta and leaf miner pests, which can be controlled by crop rotation, the use of pheromones such as pherodis tuta and other chemicals like emamectin benzoate and indoxocarb.