Plants that we call weeds are generally plants that are rather too successful for our liking - pushing out the plants that we do want to thrive, popping up in places that are not of our choosing. Their presence can range in significance from being a serious menace to ecosystems through to the rather trivial problem of being unpleasing to the eye. Generally weeds are plants that have been introduced by people to an area where they were not previously growing. One that is grabbing attention at this time of year is the onion weed, Allium triquetrum, with its profuse display of pretty white and green flowers.
There are other plants called onion weed, but this is the only one in New Zealand, it seems. It is a bulb from the Mediterranean, naturalised here in 1899 according to the New Zealand Plant Conservation Network. It grows happily in sun or shade, colonises disturbed ground, and spreads readily by seed or vegetatively.
All the parts are edible with a mild onion-y flavour and when you are weeding or walk on it you get the pleasant (to me but not to all people) aroma of garlic.
Food forager Johanna Knox discusses its uses with Richard Scott on This Way Up on Radio New Zealand.
Attractive and edible, but alas, rather too successful. In Victoria Australia it is listed as an invasive noxious weed. It doesn't seem to have achieved that status here - yet.