Tiarella trifoliata var. unifoliata, commonly known as Oneleaf Foamflower, is a perennial herb native to the cool, moist, and shaded forest floors of the Pacific Northwest, including the Northwestern United States and Southwestern Canada. It is particularly adapted to the understory of coniferous forests, thriving in humus-rich and acidic soils. This plant typically grows at a moderate rate to a height and width of 0.5-1 feet (0.15-0.3 meters). Oneleaf Foamflower is characterized by its attractive foliage and delicate, white, star-shaped flowers that bloom in the spring, creating a carpet-like effect. The flowers are showy and borne in loose, airy spikes, adding a light and graceful texture to woodland gardens.

Oneleaf Foamflower is valued for its ornamental foliage, which often features marbled or veined patterns, and for its ability to form dense ground covers in shady areas. It is commonly used in shaded borders, woodland gardens, and as an underplanting for larger shrubs. This plant is relatively low-maintenance, requiring medium amounts of water and thriving in medium or slow-draining clay or loam soils. It prefers full shade but can tolerate dappled sunlight. While generally disease-resistant, it can be susceptible to powdery mildew in overly humid conditions. Gardeners should be aware that it can spread by runners, forming colonies, which can be beneficial for ground cover purposes but may require management to prevent unwanted spread.CC BY-SA 4.0