These have been erupting all up and down my street. I had never seen them before, but I guess that's more on account of never having noticed, since obviously they were probably there last year as well. They are very pretty purplish-white flowers with dark purple streaks down the backs of the petals and sepals, and occasionally the stripes "bleed through" to the front. The pistils and stamens are hidden a bit in a tube that extends back behind the plane of the petals, which I think adds a unique touch to the bloom. The most unique thing about these plants, though, is the fact that when you crush the leaves or pick the flowers, it gives off the most overwhelming scent of onions. And indeed it is in allioideae, the onion family.
The plant is called Ipheion uniflorum. It was formerly classified as Tristagma, so you might find it under that name as well. Commonly though, it's just referred to as spring starflower. Like other onions (and indeed like all amaryllids), it's a bunching, bulbous, and simple-leaved. Unlike other onions though (and by this I mean the true onions), each flower stem only has one bloom, though each plant can send up more than one flowering stem. Because of the lateral growth due to the bunching bulbs, it forms occasionally quite large mats, although it'd have to be left alone for quite some time to really start taking over. A lot of people on the street have already been mowing the poor little things over, cloaking the entire street in the scent of cut chives.
You can probably guess my opinion of people who callously mow over wildflowers.