Dong leaf traditionally wraps bánh chưng, the square Vietnamese sticky-rice cake for Tết.
Bánh chưng is made from glutinous rice, mung beans, and seasoned pork. The ingredients are packed into a square mold and wrapped in layers of dong leaves before being boiled for many hours. Dong leaves give the cake its characteristic green exterior and a subtle herbal aroma.
The cake is strongly associated with northern Vietnam and the Lunar New Year. Its square shape is traditionally linked with the earth in Vietnamese cultural symbolism, while the related cylindrical bánh tét is more common in southern and central regions. Banana leaves may appear as substitutes outside Vietnam, but they are not the traditional wrapping for bánh chưng.