Last weekend, when I should have been writing grant applications, I was dragged out for a bush-walk. However, my arm didn’t have to be twisted too hard, since it was a fine day and the track between Kiriwhakapapa and Blue Range is lovely (although steep).

Alseuosmia pusilla was abundant along the track. This is a very interesting little shrub. It looks a LOT like a juvenile of the completely unrelated horopito (Pseudowintera colorata) tree, which is also known as pepper tree because its leaves have a peppery taste.  (Horopito is sometimes also called “ice cream plant” to the uninitiated…)

It’s been suggested that this is a case of mimicry, the palatable Alseuosmia pusilla mimicking the unpalatable horopito, although this is controversial.

The similarity is certainly sufficient to often fool me, until I take a good look (the Alseuosmia flowers and fruit are very different to horopito) or have a little taste of the leaves.

There are only a few species of Alseuosmia, and they are all only found in New Zealand. They are fantastically morphologically-variable, and it can be difficult to work out which species is which. The tallest species, A. macrophylla (toropapa or karapapa) has big flowers that are often very colourful. They are also heavily scented, such that the plants are often smelt before they’re seen!

Te Papa’s collection includes a specimen of Alseuosmia macrophylla collected in 1769 during Captain Cook’s first expedition to New Zealand.  You can view it here.