Caltha is a genus of flowering plants commonly known as marsh marigolds. These plants are typically found in wetland areas, such as marshes and along stream banks. They are characterized by their bright yellow flowers and large, heart-shaped leaves. Caltha species are often among the first to bloom in spring, providing an important food source for early pollinators. The most well-known species is Caltha palustris, which is native to North America and parts of Europe and Asia. Caltha plants thrive in moist, acidic soils and can grow in full sun to partial shade. They are often used in garden landscapes to enhance wet areas and attract wildlife.