Prostrate broom – a delicate beauty

 

Prostrate Broom Carmichaelia appressa. Photo courtesy of Steve Attwood, Christchurch.

Prostrate Broom Carmichaelia appressa. Photo courtesy of Steve Attwood, Christchurch.

 

Very little of our original native coastal vegetation has survived, as farming and urban settlement have encroached upon natural coastal locations. Native species such as pīngao, flax and ngaio have, in many places, been replaced with marram grass, lupins and pine trees.

 

One that has survived on Kaitorete Spit is the prostrate broom Carmichaelia appressa, which is endemic to the gravelly, sandy loam, the stabilised sand dunes and the ridges of sand along the spit.

 

Prostrate broom (also known as Appressed broom), is a fast-growing native shrub that grows to a height of around 0.3m and has a spread of 0.5m. From October to January it is distinguished by its dense, pea-like, scented white and purple flowers. It grows in sprawling yellow-green mounds of apparently leafless branches.

 

In 2012, it was listed as “At Risk – Naturally Uncommon” and unfortunately, its natural habitat on Kaitorete Spit is very susceptible to damage by off-road bikes and 4WD vehicles. However, a large part of its habitat is protected within a scientific reserve.

 

The Carmichaelia genus of New Zealand brooms includes 24 plant species belonging to the Fabaceae or legume family. All but one (Carmichaelia exsul), are native to New Zealand. The genus has a range of forms from trees to prostrate species a few centimetres high and mature plants are usually leafless, with stipules fusing into scales to replace leaves.

 

Carmichaelia are named after Captain Dugold Carmichael, a Scottish army officer, who studied New Zealand plants.