For most of the year kūmarahou is a rather unremarkable looking plant, hiding in plain sight with its dull-green velvety leaves. In late spring however, the plant bursts forth with clusters of creamy-yellow flowers – colouring the landscape in sunny blossoms. For Māori this was the signal that it was time to plant kūmara.
The English name – Gumdigger’s soap – comes from it’s use on the Gumfields of Northland. The gumdiggers were hardy men, living a rough existence in dry scrub forest, hoping to make their fortunes with a strike of kauri gum. Living off the land, they made a discovery that was already known to Maori – that by rubbing the flower heads of kūmarahou with a little water they could create soap. This soap is the result of compounds called saponins – which are occasionally used in modern dish wash and detergents. Kūmarahou flowers have also been used by farmers and motorists that have broken down on the roadside as an emergency soap to clean greasy oily hands.
The plant was highly admired by both Māori and Pākehā for its medicinal qualities, and kūmarahou played an important role in rongoā. Kūmarahou leaf tea was used as a general tonic to treat a variety of ailments, but was considered particularly effective for chest complaints; coughs, colds, bronchitis, pulmonary tuberculosis, heartburn and asthma. It is said to have a beneficial effect on the kidneys and was even used to treat arthritis and menstrual pain. The leaves could also be soaked in water and applied to wounds and skin irritations, and were said to speed the healing process.
The bitter taste of kūmarahou tea has led to its use in alcoholic beverages as well. Prior to the arrival of Pākehā, Māori had almost no exposure to alcohol at all, though some iwi are reported to have drunk the fermented juice of tutu berries and kiekie flowers. The arrival of European liquor spurred a newfound interest in developing native brews and Māori developed the kūmarahou tonic into a type of homebrew – paikaka. Pākehā settlers and missionaries were also on the lookout for innovative new alcohol recipes, and found that the leaves made a good substitute for hops when brewing beer.
Find out More:
New Zealand Plant Conservation Network: Pomaderris kumeraho
Ngā tipu whakaoranga – Māori Plant Use Database: Kūmarahou
A recipe for Kumarahou beer can be found in:
Murdoch Riley (1994) Māori Healing and Herbal: New Zealand Ethnobotanical Sourcebook.