Kowhai - New Zealand National Flower

Division: Spermatophyta
Subdivision: Angiosprermae
Class: Magnolpsida
Subclass: Magnoliidae (Dicots)
Superorder: Fabiflorae Order: Fabales
Family: Fabaceae - Legumes

Three species in New Zealand
Sophora microphylla
Sophora tetraptera
Sophora prostrate (shrub, not used medicinally)

S.microphylla and S.tetraptera have the same medicinal properties. Literature favours one or the other, but both are used for the same conditions. The medicinal properties in this article therefore refer equally to both species.

Botanical description S.microphylla is common and widely distributed throughout New Zealand and the Chatham Islands up to 500m above sea level. The tree grows up to 10m high, the trunk up to 60cm diameter with spreading branches. It has small flowers and leaflets. The leaves are small, round and in 20-40 pairs. S.tetraptera is the large leaf variety, less pars and more elongated leaves. It is found in the North Island. Both grow at streamsides and lakes, on forest margins and in lowlands as a single tree or in groups.

Maori Mythology Kowhai is the Maori word for yellow.
It is said that to Kowhai sprung from the shreds of the cloak of tohunga Ngatoro-I-rangi of the Te Arawa canoe on its arrival to New Zealand. Te Arawa tells of a young tohunga asking a girl to marry him while they were sitting under the bare branches of a Kowhai tree in the month of August. She replied that she would only marry if he could perform some brilliant act. The young tohunga said "I will show you what I can do. I will cause this tree to spring instantly into flower before your eyes". Then he used all his powers and made the tree burst into yellow bloom. His final touch caused a ring of yellow blossoms to appear around the dark hair of the girl. Ever since, say Te Arawa, the Kowhai has flowered on bare and leafless branches. Kua ura te ao te kowhai - The kindling of Kowhai blazes.

Parts used Inner/outer bark on the sunny side, root bark and leaves

Chemistry The constituents in the bark are matrine cytosine and phytoalexin 3-hydroxy-8,9-methyl-nedioxypterocaprin. Roots have tetrapterol ABCD and E, kenusanone A, lespedol B, euchenone, lonchocarpol A, cajanone, isoneorautenol, pentacosanyl, caffeate. S.microphylla contains hesperidin. Hesperidin is associated with strengthening of blood vessels and is a member of the vitamin P (bioflavaniod) group.

Medicinal uses Kowhai is very much like senna, it is purgative in larger doses and a tonic and emetic in lesser doses. The seed is the most dangerous part causing excessive purging (dysentery) in small quantities if casing is compromised.

According to 'A field guide to the Native Edible Plants of NZ' by Andrew Crowe and 'Simply Living' by Gwen Skinner, this plant is not to be taken internally as it will cause diarrhoea and abdominal pains. This is not however mentioned in 'New Zealand Medicinal Plants' by Brooker, Cambie and Cooper.

Mother Aubert lists Kowhia S.tetraptera as: Tonic to stimulate nutrition and permanently increase systemic tone (leaky gut), energy (chronic fatigue), vigour and strength. Purgative to evacuate the bowels, more drastic than a laxative or aperients. Ease itching with a decoction of inner bark. An anti-febrifuge.

As a tonic - Traditional uses
An infusion (of Kowhai bark and Manuka leaves) is drunk for internal pains and applied externally to pains in the back and side. A lotion can be prepared for muscular pains. Internally it eases symptoms of colds and the pain of sore throats and toothache. Suggesting anti-inflammatory properties.
Externally it soothes itching skin and shingles. An infusion of Kowhai bark mixed with Kowhai ashes was made into a paste and applied to all skin conditions and was particularly effective against ringworm.
It is widely reputed for aiding setting new fractures, halving healing time. The bark is crushed and steeped in boiling water for some hours, and then a poultice is applied externally. Externally the bark steeped in water as a poultice for bruises, sprains, tumours and wounds.
The tincture in water may relieve dandruff.
Soaking in a bath with strips of bark can relieve blood poisoning.
There is a detailed case of George Nepia who was threatened with surgery but chose traditional Maori medicine to treat a badly infected leg. Two sacks of bark was collected, bruised, and boiled until dark tan. The decoction was placed in a bath and George bathed in it for an hour, his leg was then nicked all along it, and more hot decoction was added to the bath. After another hour the leg was bleeding dark blood, the healer cried out "Ka pai tau waewae" (Your leg is good). His fast recovery and return to sports in 14 days, astounded doctors whom predicted 6 months at least, maybe never.
Traditionally to treat Gonorrhoea a tree on a hillside was chosen and a root running towards the sun was selected. The outer rind was scrapped off and the second skin removed from the central core, the juice was expressed. A small teaspoon was taken three times daily reputed cured gonorrhoea in a couple of days.
The leaves were boiled and the liquid was used to bathe a wound before covering it with the bruised leaves as a bandage.
A good source of traditional uses is "Moari Healing and Herbal" by Murdoch Riley, 1994.

It is listed botanically as a poisonous plant, though woth correct preparation and knowledge it may be used medicinally. This plant reflects our ability as trained herbalists to utilise nature for its best use without harm. Kowhai is not a common-used herb in western herbal medicine.

For those interested in the intelectual significance of Maori mythology and Toanga in todays politics visit
www.waitangi-tribunal.govt.nz/doclibrary/wai262/matauranga-maori/chapt06.pdf

DOSE
Tincture 1:5 3-15mls per week (this dose has NO purgative effects) Alternatively 10-20 drops per 100ml Sips of the infusion of the inner bark

Leanne Halliwell BHSc(CM), ND, BCApSc
References New Zealand Herbs notes, by Self Heal (1998)
Maori Healing and Herbal, by Murdoch Riley (1994)
Which Native Tree? A simple guide to identification of New Zealand native trees, by Andrew Crowe (1992)
Eagle's 100 Tress of New Zealnd herbs, by Audrey Eagle (1978) www.aoteamoana.co.nz/native/native.html
www.rnzih.org.nz/pages/poison.html