Beach Bean

We're slowly becoming familiar with the plants of our new sub-tropical home. This pea flower grows vigorously close to the shore. I'm fairly sure it's Canavalia rosea (Beach Bean, among other common names) which I read is found on many coastlines in the tropics. Wikipedia says that the buoyancy of the seeds allows them to be distributed by ocean currents. This one grows on the summit of Lennox Head. The flower is about 2 cm across.