Pittosporum crassifolium Banks & Sol. ex A.Cunn.

국표에 없다.

Pittosporum crassifolium, karo, stiffleaf cheesewood, kaikaro or kihiki is a relatively fast-growing large shrub or small tree with an erect, fastigiate growth habit. It is native to New Zealand.

This species is self-supporting with a simple form that can grow up to 10m tall. Pittosporum crassifolium is part of the wider Pittosporaceae family, which has over 160 species in the southern hemisphere.

Description

The leaves on this species are approximately 5-10x2-3cm and are oval shaped, dark green and leathery with grey tomentum (fine hairs) on the undersides of the leaves including the petioles and inflorescences. This tomentum provides protection against coastal winds by preventing salt damage and moisture loss.

The leaves are simple and are alternately arranged and are very dense at the furthest point away from the stem. The leaf margins are recurved, thick and leathery (hence the name crassifolium which translates from Latin to "thick leaf") and they often show signs of insect damage. The apex of the leaf can vary from being obtuse (blunt and rounded) to acute (sharp and tapered) The petioles are the stalk between the leaf and the stem, and they measure approximately 4-14x1-3mm.

When in ideal growing conditions, karo can grow into small trees (up to 5 metres (16 ft)) with multiple trunks. The bark on karo is dark brown and black and has distinct lenticels which allow for breathing. Juvenile plants often appear different from the adult form as the branchlets are covered with tomentum until they mature and become darker.

During the spring to early summer, karo produce fragrant burgundy red flowers that are around 10cm long with long stalks and are borne in terminal umbels meaning that they grow in clusters, similar to the shape of an umbrella. These terminals are also hairy, unlike the flowers which gives this plant extra protection from salt spray. The flowers of the karo are unisexual, meaning each terminal produces between 5-10 male flowers and up to 5 female flowers. A distinct feature of the karo flowers is the fragrance which “pervades the evening air”. The sepals of the flower (the green part below the flower bud) measure approximately 7-11mm x 1.5-3mm and they have small cilia (hairs) and brown tomentose along the margin.

After the karo has flowered, it produces green capsules, that then develop into woody seed pods with black seeds that are sticky and shiny and are protected inside a trigonous capsule (three angled) which measures approximately 25mm x25mm and is filled with black glutinous matter.

Although endemic to the upper North Island of New Zealand, this species has now spread both nationally and internationally and is now considered a weed in areas where it is non-endemic.

The main way of distinguishing Pittosporum crassifolium from other native New Zealand pittosporums such as Pittosporum tenuifolium and Pittosporum eugenioides is the distinct grey tomentum on the underside of the leaves which differs from these other species. The leaves of Pittosporum crassifolium also have less undulation than these other species.

Pittosporum crassifolium - Wikipedia