Kowhai

Taxobox
name = Kowhai Tree

---

image_width = 250px
image_caption = Kowhai flowers
regnum = Plantae
divisio = Magnoliophyta
classis = Magnoliopsida
ordo = Fabales
familia = Fabaceae
subfamilia = Faboideae
genus = "Sophora"
subdivision_ranks = Species
subdivision = "S. chathamica"
"S. fulvida"
"S. godleyi"
"S. longicarinata"
"S. microphylla"
"S. molloyi"
"S. prostrata"
"S. tetraptera"

Kowhai are small, woody legume trees native to New Zealand. There are eight species. "Sophora microphylla" being the most common.

"Sophora microphylla" has smaller leaves (5-7mm long by 3-4mm wide) and flowers (2.5-3.5cm long) than "Sophora tetraptera" which has leaves of 1-2cm long and flowers that are 3cm-5cm long.

Kowhai trees grow throughout the country and are a common feature in New Zealand gardens. Outside of New Zealand, Kowhais tend to be restricted to mild temperate maritime climates.

Description and ecology

Most species of Kowhai grow to around 8 m high and have fairly smooth bark with small leaves. They have horn-shaped yellow flowers, which appear in early spring.

Their nectar is a favourite food for Tui and Bellbird.

The very distinctive, almost segmented pods, which appear after flowering each contain six or more smooth, hard, yellow seeds. These seeds can be very numerous and the presence of many hundreds of these distinctively yellow seeds on the ground quickly identifies the presence of a nearby Kowhai tree.

Unusually for New Zealand plants, some species of Kowhai are deciduous, losing their tiny, dull green leaves each winter. Many other Kowhai trees lose most of their leaves immediately after flowering in October or November but quickly produce new leaves.

"Sophora" is one of the four genera of native legumes in New Zealand; the other three are "Carmichaelia", "Clianthus", and "Montigena".

Uses

"Sophora prostrata", sometimes called "Little Baby", is used as a Bonsai tree. It grows up to 2 metres high, has zigzaging stems, and sparse smallish leaves. [http://www.ipps.org/Papers/NewZealand%5CHughes.PDF]

The Kowhai is the national flower of New Zealand.

Cultivation

You can grow kowhai from seed or tip cuttings around late autumn(fall) and early winter.

From Seed

The seeds are little hard yellow seeds and these need to be treated specially to make them grow. In nature kowhai seed erodes away as it tumbles down streams and then when it comes to rest it germinates. But we have to break through the hard casing to make it germinate.

The best thing to do is to get a pair of nail clippers and then take each seed and carefully make a nick-along the brown backbone of the seed as it is one of the easiest places to cut. But make sure you don't nick the inner kernel of the seed because that destroys it. You could use a knife but these are slippery little things!

Then put it to soak in water overnight. By the next day it should be swollen and ready to plant. Fill a tray with seed raising mix - it has to be coarse for good drainage. Water the potting mix tray to avoid disturbing the seeds later. Scatter the seeds over the top of the seed mix then cover them with their own depth of seed mix.

They'll germinate in a couple of weeks.

From Cutting

Look for the growing tip on each branch.

Take a cutting that is approximately a hand's width, tip of thumb to end of outstretched little finger.

Strip off all the lower leaves, but leave the top growth on. Trim the cutting back to a node, where a leaf was stripped from the stem.

Put potting mix in tray and give it a thorough watering.

Then stick the cuttings in the potting mix - bury about 2/3rds of the cutting in the pot and put the pot into a plastic bag to keep an even humidity.

They may take 6 weeks to 2 months to root. Once they have rooted though, transfer them to individual pots and then plant them out in spring.

Etymology

"Kōwhai" is the Maori word for yellow, which in turn gives the tree the name due to the colour of the flowers.

Dangers

The Kowhai's bark and seeds, are poisonous. [cite web
title=Poisonous Plants at the Royal New Zealand Institute of Horticulture
url=http://www.rnzih.org.nz/pages/poison.html
accessdate=2008-05-20
]

References

External links

*
* [http://www.rhizobia.co.nz/taxonomy/legume.html The Current Taxonomy of New Zealand Legumes]
* [http://www.virtualoceania.net/newzealand/photos/flora/kowhai/ Kowhai photos]
* [http://www.ipps.org/Papers/NewZealand%5CHughes.PDF Sophora – "The Kowhais of New Zealand"] by Denis Hughes, "IPPS Proceedings Volume 52", 2002, retrieved July 1, 2006