This pretty flower is one of those examples of 'can't leave well enough alone,' as you will find it variously listed as Acacia angustissima, or Acaciella angustissima. At least they've agreed on the narrow leaves! Which some of the common names agree on, as well, since it's sometimes called Fern Acacia, also Prairie Acacia. That latter threw me off a bit, as I photographed this specimen in a mixed oak and cedar woodland, fairly open and park-like, which is explained by the plant's preference for wood's edges as well as the full sun of the prairie meadow.
In dappled shade, the plant is smaller than it would be in full sunlight. Specimen photographed in Cameron Park, Waco, Texas.
The white flower, with it's flossy silken stamens, caught my eye first, above the delicate leaves. But as I stepped closer to photograph it, I was pleased to also capture my first native pollinator in Texas - one of my favorites. The little green halictid bee was quite happy wrapped up in fluffy flower.
It's a pity the Halictids are so poorly studied. They range over most of the North American habitats, and are equally happy on any flower they can get. Unlike some species who will starve and die if they can't find their choice of host plant, the tiny jeweled sweat bees are equally happy with native or introduced species.
Halictid bee on Acacia angustissima (Prairie Acacia)