Also called Botanical tulips. These tulips naturalise if planted in a sunny, warm spot. Allow the foliage to die completely after flowering so that nutrients can be absorbed into the bulb. In summer, they need warmth for flower bud development for the following year. Wild tulips can also be planted in the grass, wait until they have completely died off before mowing.
The Woodland Tulip, (Tulipa sylvestris), a native plant, is an exception, it also naturalises in places with less sun.