Oenothera caespitosa
Oenothera caespitosa, known commonly as tufted evening primrose, desert evening primrose, rock-rose evening primrose, or fragrant evening primrose, is a perennial plant of the genus "Oenothera" native to much of western and central North America, in habitats such as talus slopes and sandy plains. It is normally night-blooming. The plant is considered good for rock gardens. There are many subtaxa, referred to as subspecies or varieties. Description. "Oenothera caespitosa" grows to 10 centimeters (4 inches) tall. It produces a rosette of lobed or toothed leaves each up to long around a woody caudex. It has no  stems, with flowers and leaves growing directly from the root crown. The four-petaled white flowers open at dusk and wilt the next morning, turning pink. The petals measure up to in width and length. A notch gives them a heart shape. Ecology. The plant is a larval host to the white-lined sphinx moth. "Oenothera caespitosa" is dependent on hawkmoths, including the five-spotted hawkmoth ("Manduca quinquemaculata") for pollination. Similar species. "Oenothera deltoides" is very similar, with short stems and slightly smaller flowers.