Is this just Viola hederacea? That species is extremely common here, at the moment there'd be 1000's of them flowering. But this one caught my eye due to its diminutive size, the whole flower being around 5mm across. It was also growing alone from forest litter, whereas Viola hederacea will typically form quite large colonies.
Numerous C. carnea were in the immediate area but this one stood out. Very pink (the rest were pale pink to white) and the sepals appeared different, as did the way the flower 'sat' on the stem. It was also smaller than those around it. Someone has suggested C. vulgaris?
Same individual as the sighting below. Found during routine track maintenance.