Mexican evening primrose is a herbaceous perennial with white to pink flowers that mature to rosy pink. It grows to 10 to 20 inches tall and 18 inches wide, with erect to sprawling stems. Narrow, lance-like, medium green leaves sometimes have small lobes near the leaf bases. Flowers open in the evening and remain open to late morning (all day if overcast). Flowers are followed by oval, ridged, seed capsules. It can be a little aggressive, but in hot, dry parkstrips, that's a fabulous quality.
Grow in full sun in well drained soil. Tolerates clay or sandy soils, as long as they are well drained. Frost tolerant to 10 F. There are a number of cultivars available, including 'Rosea' selected for its consistent pink coloring, and 'Siskiyou,' slightly shorter than the species but with blooms that last all day.