It looks like the common white/cream Freesia, widely naturalised in south-eastern Australia. It has been known as F. alba or F. refracta, but my understanding is that it is probably an old hybrid with one or both of these species in its parentage. Around Sydney you can find populations with a lot of colour variation, some plants tending more to violet or pale orange.

If it is the common freesia, it would have the the distinctive perfume that the old fashioned freesias have.

Thanks to Tony & Mallee for help with the plant in the photo. I haven't seen, or smelt the plant but will pass the info along.

Thanks again.

This is one of the plants that are a feral weed or a "New Australian Native" depending on your viewpoint. They've taken to the bush with vigour, and, realistically, we'll never be rid of them. Perhaps we don't want to. We can only hope that they're not squeezing some shy little native out of existence.
Trish