Euphorbia terracina does not spread vegetatively, proliferation is by seed only. Seed is scattered over several metres when the ripe fruit bursts open explosively. Long distance dispersal is mostly by soil, especially in crushed limestone used in road and path construction. Seed can also be transported by water movement or carried by animals and machinery.
Knowledge of seed longevity in the soil is important in planning a control program. Generally speaking a seed bank, if not allowed any further recruitment, would probably last 3-5 years dependent on the severity of the winters. The rapid onset of a cold winter may force seed into dormancy before having the chance to germinate, extending the life of the seed bank.
Limestone: Seed recruitment from external sources is the most common cause of new infestations and the use of limestone in paths and access roads is a major source of these incursions. If crushed limestone is proposed for use in this manner it should be obtained from a verified Euphorbia terracina free quarry or supplier and preferably not from material that has been exposed for any period of time, hence minimising the possibility of contamination.
Picture by Kate Brown
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Technical enquiries to: kate.brown@wrc.wa.gov.au