Sophora tetraptera (Large Leaf Kowhai, New Zealand Laburnum)


Michael's Opinion

A very unique plant, with magnificent yellow flowers, very commonly argued to be New Zealand’s national flower. The leaves of this tree are interestingly shaped, but be wary when handling this plant, especially the fruit, as it is toxic to humans.

Botanical Information

FamilyFabaceae
GenusSophora
Speciestetraptera
CategoryWoody
TypeTree (evergreen)
OriginNew Zealand.
Pronunciation

Details

USDA Hardiness Zone9-10
USDA Hardiness Ref.
Canadian Hardiness ZoneRequires cool season protection under glass.
Canada Hardiness Ref.
RHS Hardiness ZoneH4 - H2
RHS Hardiness Ref.
Temperature (°C)(-4) to 4
Temperature (°F)25 to 40
Height8 m
Spread4 m
GrowthSlow
Flowering PeriodMay, June

Description and Growing Information

General DescriptionA tall, frost hardy, woody perennial evergreen that flowers in the late spring until the end of summer. The flowers are papilionaceous shaped when in full bloom. The leaves are green in colour with an odd pinnate shape.
ID CharacteristicOne of the most vital points when identifying Sophora tetraptera is its extremely distinctive fruit. The fruit looks like beans or peanuts and hang in clusters of 6 or more.
ShapeUpright.
LandscapeA flowering accent plant in city parks and is suitable as a coastal or seaside tree.
PropagationSeeds should be completely ripe when sowing, if the seeds have been stored for a prolonged period, leave them overnight or for about 12 hours in hot water. Sow into potting trays, preferably mid-winter in a greenhouse or a protected and heated building. Once seedlings are big enough to handle, carefully transplant into individual pots and continue to grow in individual pots for the next 2 years. Seedlings then can be planted into their final location in early summer.
CultivationWell-drained fairly fertile growing media with full sun.
HabitatStream edges and lowlands of the North Island of New Zealand.
Bark/Stem DescriptionBark is green to brown with a bumpy texture.
Leaf DescriptionA medium to dark green colour on top with a light green on the underside, odd pinnate in shape.
Flower DescriptionLarge bright yellow flowers that bloom in sets of 5-10 racemes every mid-October lasting until mid-November, 3 -5 cm long.
Fruit DescriptionVery distinctive, almost segmented pods, appear after flowering each contain 6 or more smooth, hard yellow seeds.
Colour DescriptionA reddish brown colour, with vibrant yellow flowers, fruit and seeds.
Texture DescriptionThe spread and shape of the leafs gives the tree a fuzzy textured look from a distance. The overall texture is medium.

Photographs