Answer: Unfortunately, based on your description I am not able to tell you what your plant is. A daylily (Hemerocallis) has arching, grassy textured foliage; the flowers appear at the tip of a long skinny stem (scape) that grows up from the center of the foliage. Each flower lasts just one day. White is an unusual color for a daylily.
There are several photos (including close up and landscape view) of a typical daylily in the Monrovia plant listing for a daylily called "Fairy Tale Pink"; if you enter the words Fairy Tale Pink into the search box, you will see the listing for it. Click on that and then on the tiny photos.
If this is not the type of plant, I would suggest you take some photos of it and work with your local professionally trained nurseryman and/or county extension to try to identify it. I hope this helps!
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