Pest plant - Boneseed

Description

• erect perennial shrub to 2m, or much taller in sheltered sites, with a woody trunk
• leaves are 3-8cm long, bright green and waxy, with irregular serrated edges
• flowers are bright yellow and daisy-like
• fruits are dry berries 6-8mm in diameter; they turn from green to black, then flake off to show a white inner coat
• each fruit holds one seed which is bone-coloured and very hard.

Why is it a problem?

• serious threat to native vegetation (rarely found in crops or pastures)
• establishes in many native vegetation types (scrub, woodland and forest)
• establishes readily on disturbed sites such as cleared, cultivated or burnt areas
• invasive due to rapid growth, a large seed store in the soil, and the ability to regenerate after fire
• dense stands drastically alter the habitat of native birds and animals.

Distribution

• Eyre Peninsula – isolated patchy populations
• Northern pastoral – one record in Flinders Ranges
• Northern agricultural districts and Yorke Peninsula – small, isolated infestations
• Murray Mallee – isolated plants along the Murray River
• South East – isolated infestations on roadsides, reserves and some native vegetation
• Central region – widespread in the Adelaide hills.

Ecology

• not restricted by climate and will tolerate most soil types and coastal conditions
• reproduces by seed, which germinates at any time of year but mainly in autumn
• grows rapidly over winter and some plants flower in their first year
• flowers are formed in late winter and spring and the ripe seeds are shed in summer
• the hard seed coat allows seed to remain dormant in the soil for many years
• a fire will stimulate all the seed to germinate at once.

How it spreads

• birds eat the fruit of boneseed and transport it to other locations
• rabbits, foxes, and cattle also eat the fruit and spread the seeds in their droppings
• contaminated soil and water can also carry seeds.