Anchor Plant - Colletia paradoxa
This unusual plant, Colletia Paradoxa with its flattened branches and sharp spines is a native of Brazil and Uruguay. It is rarely planted in gardens.
There is a specimen in the Geelong Botanic Gardens, which suggests that this plant may have been part of Mueller's experiment with acclimatization.
It grows in the bed to the east of the cannon and has clusters of sweet smelling white flowers in Autumn.