Rubia akane Nakai.
This perennial vine plant that grows in the plains and mountains all across Korea grows to about one meter in height and has reddish yellow roots. Pale yellow flowers with a diameter of 3.5 to 4 mm bloom from June to August. The fruit of the flower is round and ripens into a black color. Its roots are used as a purple colorant.

Rhus javanica Linn.
Also called Rhus chinensis, this deciduous tree grows in the foothills of mountains and ravines across the nation. The tree grows to about seven meters tall and has insect wax on the leaves, which is called Malaphis chinensis. The yellowish white flowers blossom from July to August and bear yellowish red fruit in October which turns white when fully ripe. Malaphis chinensis is used for producing a pale yellow dye.

Sophora japonica Linn.
Originally from China, this deciduous tree is commonly known as the pagoda tree. The pale yellow flowers bloom in August and bear fruit in October. The flowers of the pagoda tree are used for producing a yellowish dye.