Urtica ferox G. Forst.

국표에 없다.

Urtica ferox, commonly known as tree nettle and, in Māori, ongaonga, taraonga, taraongaonga оr okaoka is a species of nettle endemic to New Zealand. Unlike the other species in the genus Urtica found in New Zealand, all of which are herbaceous, ongaonga is a large woody shrub that can grow to a height of 3 m (9.8 ft), with the base of the stem reaching 12 cm (4.7 in) in thickness. It has large spines that can result in a painful sting that lasts several days.

The plant is the main source of food for larvae of the New Zealand red admiral butterfly.

Description

U. ferox can grow to a height of 3 m (9.8 ft) with the base of the stem reaching 12 cm (4.7 in) in thickness. The pale green leaves are very thin like a membrane and the surface of the leaf, stems and stalks are covered in stiff stinging hairs that can grow up to 6 mm (0.24 in) long. These spines are prominent along the salient mid-vein and leaf margin. The leaves range from 3–5 cm (1.2–2.0 in) in width and 8–12 cm (3.1–4.7 in) in length, these are oppositely arranged and there are two stipules per node. The leaf shape is ovulate-triangulate with a serrated leaf margin each bearing a spine of up to 1 m (3 ft 3 in). The spines covering the leaf surface, stem and stalk are generally no larger than 6 mm (0.24 in) in length, the spines on the older darker bark are smaller and softer - these don't cause a sting. This nettle is winter deciduous in cold climates, evergreen in mild climates and can lose its leaves in drought conditions if it is growing in shallow soils.

Flowering occurs from November to March and because U. ferox is a dioecious shrub it will cross pollinate, with transferral between the flowers enabled by the wind. Pollen grains are collected by the densely packed stigmas on the flowers and seed dispersal is carried out by rolling, wind, and by birds. The fruit, which are achenes, mature in January, each containing one 1.5 mm long, brown coloured, ovoid-shaped seed which takes one month to germinate. In his study on the germination behaviour of 5 different vascular seeding species, C. J. Burrows found that U. ferox had the lowest germination rate of 59% compared to >85% for the other similar species. He surmised that it is capable of building up a large seed bank in the soil which may survive for several years, citing that European species in the genus Urtica produce seed banks.

Urtica ferox - Wikipedia

https://youtu.be/hZKIozK1H68?t=125