An iconic kiwi emblem, the flowers of the kōwhai tree are considered by many to be the unofficial national flower of New Zealand. Every year their gradual emergence around the Dunedin streets gives a signal that winter is at its end.

The production of colourful flowers is the main advertising mechanism of many plants. Like a bright storefront sign on a dark evening, the kōwhai’s yellow blooms stand out against its background, holding the promise of a reward for those who choose to approach.

Native birds such as tūī, kereru and silvereye often visit the kōwhai, enticed by the vibrant shades of yellow. For some, it’s also the scent which draws them in of the sweet, sticky prize nestled within the iridescent folds – nectar.

The honey-eater tūi especially loves the stuff. If you’ve seen a tūi feeding, you’ll notice the way its curved beak and long tongue enable it to delve into the narrow flowers. When it’s had its fill, it will be on its way, a light dusting of pollen visible across its beak.

This scattering of pollen is the reason behind all the advertising; by attracting a guest or two, the kōwhai’s pollen can be transported from the plant and hopefully to another kōwhai to cross-fertilise. So, while we can enjoy the simple beauty of the flowers, they’re a real reproductive investment for the kōwhai.

There are eight species of kōwhai, all of which are endemic to (only found in) New Zealand. The most common species, Sophora microphyllum, is what you’ll see here in Dunedin.