Puriri - Description

Description

The Puriri tree can grow up to 20 m tall, with a trunk commonly up to 1.5 m in diameter, frequently thicker, and a broad spreading crown(9). The thin bark is usually smooth and light brown in colour(1), but can also be very flaky. Puriri was actively and selectively logged in the past to provided timber for a wide range of end uses. Only the best trees were felled, leaving the gnarled puriri often found on farm paddocks. This has given the impression that puriri is incapable of growing straight, but early reports of puriri describe naturally clear boles of 15 to 30 feet (4.5 to 9 m)(5) and there are still a few trees like that left. A good example of a well-shaped tree is behind Ruapekapeka Pa in Northland.

The dark green glossy leaves of puriri are palmate (=palm of hand; hand like) with usually 5 leaflets, or sometimes three. The lowest two leaflets are smaller than the other three. The leaflets have domatia, little pockets where the mid vein and branching veins meet(1). Nobody is quite sure what domatia are for. The underside and veins are a lighter green. (22). Seedling leaves are much more delicate and a lighter green with serrations along the edge(4). Seedling puriri can be confused with seedling kohekohe, Dysoxylum spectabile, the most obvious difference is that puriri leaflets originate from one point, whereas kohekohe leaflets are spread along the stalk. The branches of puriri, especially the young ones, are square in cross-section.

Puriri is one of the few native trees with large colourful flowers. Many plants in New Zealand have white or green flowers. The tubular flowers of the puriri look rather like snapdragon flowers(23) and can range from fluorescent pink to dark red, rose pink (most common) or sometimes even to a white flower with a yellow or pink blush. The bright colour, the tube shape, copious nectar production and the hairs at the base of the flower tube all point towards birds pollinating this flower (the hairs stop insects from stealing the nectar). On the New Zealand mainland there is often plenty of nectar in the flowers because there aren't enough birds to eat all the nectar produced by the tree.

The flower has 4 lobes (made of 2 petals), 4 long stamen (the male part of the flower) and the style grows to be as long as the stamen after the pollen has shed. It is interesting to see how the flowers open. The petals overlap each other in the bud form. The growing stamen push the petals open. When the flower is fully open the style starts growing and reaches its full length just after the anthers on the stamen have shed all the pollen. The flowers occur in loose clusters of up to 12 flowers per cluster.

Some flowers can be found on the puriri all year round, though it does flower most heavily over winter. Ripe fruit can also be found all year round, but is more common over the summer. Puriri is a very important tree for native birds in the top half of the North Island because it provides a constant year-round food supply. Flowers and fruit are carried at the tips of the branches.

The fruit is a bright red (usually) to a pale yellow (rarely, and only on white flowered trees) "cherry". It can grow as big as a cherry, but it is unpleasant to eat - it causes the mouth to feel like dried shoe leather. Puriri fruit is not the most nutritious sort in the New Zealand bush (high in carbohydrates, not lipids, sugars or calcium), but it is always there. The seed inside is a very hard pear-shaped kernel (26) that can contain up to 4 embryo seedlings. The seedlings from one seed can germinate at the same time or be spread over a year(4). When broken, the fruit has a bright thin juice, and a faint grape smell.