A small dark red dried bean, slimmer and longer than the 红豆 it is often mistaken for. It is used mostly in Chinese medicine and medicinal soups, such as one with carp; Chinese food lore holds that it drains 'dampness'.
Chinese medicine holds that red beans clear dampness and reduce swelling.
Tips
usage
Everyday speech says 红豆. 赤小豆 is the name used in herbal medicine and on soup packs, and in shops it often means a slimmer, darker bean than the round one used for sweet red bean paste.