Black day, scientific name Solanum nigrum, was born on the roadside or in the field; It is distributed in most provinces and cities in China. All herbal medicines can clear away heat and toxic materials, promote diuresis and reduce swelling, and treat colds, fever, toothache and bronchitis. Solanum nigrum lime mixture can kill cotton aphids up to 80%; The twigs are used as pig feed. The whole grass contains solanine, solanine and other alkaloids. Leaves and olives are slightly toxic and should not be taken in excess. Black fruit is non-toxic, sweet, and tastes like fruity candy. It's delicious, and I like it, too.