Kūmarahou

Pomaderris kumeraho, or kūmarahou, also known as gumdigger's soap and golden tainui, is a plant endemic to the North Island of New Zealand. It was first described by Allan Cunningham in 1839, from material he collected from the banks of the Kerikeri River in 1826. The name is a Māori term combining kūmara, sweet potatoes, and hou, new, likely referring to the flowers being a seasonal indication that kūmara should be planted. It is a shrub with fuzzy twigs and wrinkled leaves, and dense, round clusters of small pale yellow flowers that appear for a brief three weeks between September and October. It grows in coastal and lowland areas, and in gumlands, associated with the fields of kauri gum diggers. It has many uses in traditional Māori medicine, although there is little scientific confirmation of its benefits. Infusions of the leaves have been said to relieve respiratory ailments and skin disorders. The blossoms were also a sign that toheroa should stop being harvested. Rubbing the flowers with water makes a lather, which gave the name gumdigger's soap.