This article was published in the Titirangi Tatler, April 2010
Horopito is the Maori name given to all 4 species in this genus.
It is an ancient endemic genus growing nowhere else in the world, with a primitive flower structure.
Sometimes called NZ pepper tree (a name also used confusingly for kawakawa, Macropiper excelsum), the horopito is a cold-loving plant generally found south of Auckland. In the Waitakere Ranges there are a few scattered horopito plants, some of an indeterminate form which seem to resemble its less peppery cousin, Pseudowintera axillaris. The two species are widely spread and quite common throughout the country. Often growing in the same habitat, Pseudowintera colorata is generally found in areas of higher light on the edge of the forest, while P. axillaris is a shade-loving plant growing under other trees. The leaf colouration is a good diagnostic feature, with P. colorata having a yellowish leaf with distinctive red blotches on top and a whitish, glaucous underside, while P. axillaris is a dark green above and pale below.
If in doubt as to the species, try the taste test and you will be easily convinced. If after chewing a leaf you have to rush for a glass of water, you have got the real horopito. Deceptively mild on the initial taste, Pseudowintera colorata develops a strong peppery effect that competes with chilli as one of the world's hottest spices, whereas P. axillaris is mild and quite pleasant to taste. However, it is the spicy horopito that is becoming popular in trendy restaurants.
In NW Nelson there is a third species, Pseudowintera traversii, which is a small-leaved plant that grows only 1 - 2m tall. In Northland a newly-named species, P. insperata, closely resembles its North Island cousins but has a distinct yellow midrib and rather rounder leaves.
Although they all commonly grow 2 - 3m tall, P. colorata generally doesn't get any bigger, whereas P. axillaris and P. insperata can reach 7m tall. They all have fleshy, dark red or black fruit to attract birds.
They make ideal garden plants in a suburban garden as they do not get too big and need minimal attention. Plant them on the edge of the bush or in a border and they will provide a dense screen with yet another variant of the myriad greens found in the New Zealand flora.