Charles Rooks Reserve, Mitcham.
A bit surprised to find this here. A single plant, and not sure why I didn't take a photo of the base, but the flower, hairy scape and hairy cauline leaves all fit - don't know what else it could be? Antonio Park, Mitcham.
A lone plant so probably reveg, but who knows given it's a pea species with hard seeds growing in a remnant area. Charles Rooks Reserve, Nunawading.