Calylophus hartwegii, commonly known as Hartweg’s Sundrops, is an evergreen perennial herb or subshrub native to the grasslands and open woodlands of the Southwestern USA, Northeastern Mexico, and Mexico. It typically grows to a height of 0.8 feet (0.2 meters) and can spread to about 2 feet (0.6 meters) wide. This plant forms a low, bushy mound with narrow, lance-shaped leaves. It produces bright yellow, cup-shaped flowers that bloom from late spring to early fall, adding a splash of color to the garden for an extended period. The flowers are particularly showy and can create a striking visual impact when planted en masse.

Hartweg’s Sundrops is valued for its drought tolerance and long blooming season, making it an excellent choice for xeriscaping, rock gardens, and border fronts. It is also suitable for naturalistic plantings and wildflower gardens. This plant thrives in full sun to part shade and prefers well-drained soils. It is relatively low maintenance, requiring minimal water once established. While Hartweg’s Sundrops is generally pest and disease-free, it can suffer from root rot if overwatered or planted in poorly draining soils. It is not known to have aggressive roots or to be invasive.CC BY-SA 4.0