They show up only once or twice a year and the blooms last maybe a day or two...Please pardon me if they are not true lilies. I didn't plant them, they came with the house.
They look to me like Zephyranthes, also known as Rain Lilies. The couple of times a year they show up - is it after you have had a good soaking rain following a period of dryness?
Well, one thing they AREN'T is Lilium! None of the Lilium species make straplike leaves that come out of the ground. Lily leaves all sit on the stem, with the flowers on top. And no Lilium only lasts a day or two.
I think Steve got it. How big are the flowers?
We call them fairy lilies here and they do pop up after soaking rains.. The are a nice little suprise that shows up in a garden out of the blue. Enjoy them..