Urtica Ferox commonly known as Ongaonga is a nettle. This is a woody shrub with sharp spines which are dangerous to touch and a nettle that is mainly found in New Zealand.
Overview of Urtica Ferox or Ongaonga
• This nettle is endemic to New Zealand.
• It is also known as the “tree nettle”.
• Ongaonga has woody stems.
• It has unusually large stinging spines.
• This nettle can grow up to a height of 5 m.
• The spines are so sharp that even a light touch can give a painful sting.
• This pain lasts for many days.
• For Kahukura, Bassaris gonerilla, Ongaonga is the main food plant.
• It is food for red admiral butterfly larvae which are found in New Zealand.
• It is also food for yellow admiral butterfly.
• It is noted that because of this nettle’s sting acute polyneuropathy can occur.
• The leaves are pale green.
• They are arranged opposite to each other.
• The leaves are shaped in ovate- triangular to lanceolate-triangular.
• It has pointed ends.
• The edges of these leaves are deeply and coarsely toothed.
• These teeth at the edges are about a cm long.
• The leaves are 18 to 12 cms in length.
• They are 3 to 5 cms wide.
• The nettle is a dioecious plant.
• Female and male flowers occur on separate plants.
• The nettle bears pale greenish flowers.
• They are borne on spikes.
• They are 8cms long.
• The fruit is half mm long.
• It is ovoid and brown in color and a nut.
• These nettles have strong fibres and clear juice.
Geographic Distribution of Urtica Ferox or Ongaonga
Urtica ferox grows on the:
• North and South Island of New Zealand
• Stewart Island
• West of the main divide
• East Otago
• Coastal and lowland regions up to 600 meters above sea level
Scientific Classification of Urtica Ferox or Ongaonga
• Kingdom : Plantae
• Division : Magnoliophyta
• Class : Magnoliopsida
• Order : Rosales
• Family : Urticaceae
• Genus : Urtica
• Species : U. ferox
• Binomial name : Urtica ferox
Growing/Caring conditions for Urtica Ferox or Ongaonga
• This nettle grows in fertile soils.
• It can grow in shaded areas too.
• The tree requires high nutrient soil which is high in nitrogen content.
• This is a woody shrub which tolerates temperatures down to -8 degree Celsius .
• Nettle flowers from November to March.
• This nettle is wind pollinated.
• This nettle germinates its seed when exposed to light.
• The soil surrounding it should be kept wet in order to germinate faster.
This tree has to be protected from:
• The red admiral (Brassaris gonerilla)
• Red admiral caterpillar
• The yellow admiral (Vanessa itea)
• Brushtail possum (Trichosurus vulpecula)
• Goats (Capra species)
• Deer (Cervidae family)