I know next to nothing about plants! I once spent all day digging up what I believed was a weed "tree" only find out much later it was a very well established hydrangia bush (we had just bought the house). Last year I allowed a plant to grow because I thought it looked pretty only to be told it was polk salad!! I recently bought a house and I'm trying to learn as much as I can about grass and plants. There's an interesting "flower" all over the yard and I just don't know if it's a real flower or if it's really a weed. It has several "flowers" on one plant-they close up at night and are like green "buds"....but during the day they open up and look like white flowers. They aren't actual petals, it's just the inside of the green leaf is white. I'm tempted to just pull them all up and start over with things I know (well, things I'll learn about when I buy them!), but my experience with the hydrangia bush haunts me!! THANK YOU for your help!
Is it blooming now? Euphorbia marginata is a fall plant. It sounds like it could be false garlic, Nothoscordum bivale, which doesn't exactly fit your description about the petals (even though it actually has tepals), but it does close up, is white, has several flowers on one plant, and would be all over your yard this time of year.
Not really;-) As the other person pointed out my first guess was unlikely given the time of year. Just another reason to get as many details as possible. Regards Chris