The Square Mariposa Lily is named after the large square-shaped nectary structure on the petals. You can see them as the yellow indented squares on the bottom of the petals, below the yellow hairs. Usually this species blooms with white petals with a very variable amount of red designs on them. I only know of one very small patch which blooms this lovely wine-red color. The Square Mariposa Lily is Calochortus venustus (Lily family).