Hawthorn. According to the query, Kang Hua. Com shows that purple sweet melon seeds are also called hawthorn seeds, so "melon" is hawthorn. Its leaves have solitary flowers, its fruit is oblong, and its flesh is purple-red or purple-blue. It has the smell of muskmelon of Polygonaceae, is warm and sweet, and has the effects of invigorating spleen, stimulating appetite, eliminating dampness and stopping dysentery.