BLUE or SANDPLAIN LUPIN
(Photos: E. Cousins; patch of lupins at Cape Jervis; plant in flower with seed pods; flower; seed pod)
You will see lupins flowering and setting seed at Cape Jervis right now! These weeds are becoming prolific in the area between the township and the ferry terminal.
The plants grow up to 25cm high, with an erect central stem, and leaves branching off all around. The leaves are like the skeleton of umbrellas: about 10 spokes radiating from the leaf’s centre. The blue flowers are pea-like, with a yellowy-white spot that changes to purple as the flower gets older. The flowers are followed by hairy seed pods. The 3 to 5 seed in those pods are wrinkly and brown.
This plant originated in the Mediterranean and SW Europe, and obviously thinks the climate here is pretty good as well. Though the plant will die off in the summer heat, the seeds will remain to germinate in autumn, and so the cycle goes on. Isolated plants can be removed by pulling out the single tap root. Large infestations will need poisoning.