One of those native plants that cannot be eradicated no matter how much the soil is disturbed or what is planted on top is the rain-lily (Cooperia sp.). These hardy flowers have bulbs so deep that they often remain after sod is laid or a garden created, ready to emerge and bloom when the conditions are right. There are two different types of rain-lily in this area. The white kind is found everywhere, both as a single plant appearing anyplace and in colonies. These flowers have extremely long, flat, ribbon-like leaves, and the flower grows on a foot tall stalk. Of course, they always bloom after a good rain, producing a two-inch flower followed by a small pod full of black seeds.
The other type of rain-lily occurs in large colonies, usually in closely cropped grass, and its blossoms are yellow. The petals are slightly more narrow than the other type and I've never seen the leaves of this species. The flowers just erupt on long stems and an ordinary grassy embankment is transformed into a field of yellow.