Buxus sempervirens
Box is an evergreen scrub, growing to 6 metres in height. The stems are very branched. The leaves are in pairs at the same level on opposite sides of the stem. They are 2 - 4cm long with a leathery texture and shiny appearance. The leaves are dark glossy green on the upper surface, lighter green or white beneath (variegated forms also exist). The flowers are small and pale green in colour, and are found in clusters between the stem and the leaf. The fruit are a blue green colour with a three horned capsules each containing six glossy black seeds.
Boxthorn is superficially similar, but does not have glossy, leathery leaves.It is easily distinguished by the thorns!
Widely grown throughout NZ except in very cold areas. A cultivated ornamental plant used as hedging or for edges, may also be used as individual shrubs or small trees.
About thirty steroidal alkaloids of the pregnane group have been isolated. Mechanism of action: unknown. The steroidal alkaloids are present all parts of the plants, reaching a concentration of 0.5% in the stem and the leaves. Poisonous all year.
Sheep, pigs, cattle, alpacas and horses have been poisoned by browsing the living plant or more commonly the hedge trimmings thrown into a paddock. The lethal dose for a horse is about 750 grams of leaves
Include vomiting, abdominal pain, diarrhoea, incoordination, convulsions, dyspnoea and coma. Death from respiratory failure may occur very rapidly, so the presentation may be sudden death.
Acute irritation of the gastrointestinal tract with haemorrhagic enteritis. Leaves present in the stomach and intestines. Congested lungs.
History, clinical signs and post mortem findings.
Symptomatic.
Unknown if diagnosed early and symptomatically treated. Death usually within 24 hours if a lethal dose has been ingested.
Conner H.E. The Poisonous Plants In New Zealand. 1992. GP Publications Ltd, Wellington
M.R. Cooper and A.W. Johnson 1984. Plants Poisonous in Britain and their Effects on Animals
Surveillance 2007 Box toxicity in alpacas 34 (3) 24
