Long Yan is also known as longan. The slightly sweet and neutral herb (fruit) or slightly bitter and neutral (leaf, root or seed) has been used in TCM 1. (Long Yan Gen) Roots to treat Chyluria , leucorrhea, rheumatoid arthritis, etc. 2. (Long Yan Ye) Leaves to prevent epidemic influenza, epidemic meningitis, influenza, enteritis, eczema of …