The bloom stems and structure is completely different than the Ornithogalum. I also believe that the blooms are a light lavender/pink not white.
Yeah, this has got me stumped, too. I don't know where that fill dirt came from, but I have pulled out some bulbs that were as big as 3 inches with impressive roots. Like I said, they blend right in with my daylilies until they send up a bloom scape and then I can see them. I am even wondering if they grew from seeds not bulbs originally. They do seem to grow fast. I bet they are something invasive here in Florida.