Skeleton weed (Chondrilla juncea) is a deep-rooted perennial weed native to south-western Asia and the Mediterranean. It competes with crops and pastures.
- perennial herb appearing as a rosette of dark green, toothed leaves flat on the ground in spring
- in summer and autumn it produces erect, branched, leafless stems to 1m high, with widely spaced flower heads
- each flower head is 1cm wide with numerous strap-shaped yellow florets
- seeds are 4-5 mm long with an umbrella-like arrangement of bristles on a stalk at one end
- stems ooze a thick milky substance when broken.
Why is it a problem?
- competes strongly with crops and pastures, taking water and nitrogen from the soil
- blocks up harvest machinery and causes moisture level problems in grain storage silos
- can compete with cereal crops so strongly that the crops do not reach maturity
- reduces production, and the high costs of control greatly reduce the value of infested land.
- Eyre Peninsula – widespread with dense infestations
- Northern pastoral – common in cropping areas, inhibited by grazing in the pastoral zone
- Northern agricultural districts and Yorke Peninsula – scattered
- Murray Mallee – widespread
- South East – widespread in north, small infestations in south
- Central region – occasional occurrences.
- three types are found in Australia – narrow leaf, intermediate and broad leaf
- reproduces by suckers from a deep, thin taproot but is also a prolific seeder
- deep-rooted perennial, grows in summer by tapping soil water reserves
- stems grow from the centre of the rosette, flowers are only open for one day in summer but seed is produced continually over several months
- above-ground growth dies off in autumn and new rosettes form from the taproot and lateral roots.
How it spreads
- mostly spread by wind, but can also be carried on produce, vehicles, clothing or livestock
- root fragments can be moved during cultivation, causing further spread.