Gillenia
Two species growing in moist and dry woodlands, from Canada and eastern North America. In late spring, early summer, star-like white, or less so pink, flowers in profusion. Attractive serrated foliage, on dark stems, often upright, or scrambling through other plants. Good for a woodland garden, but will happily take sunnier spots, in a retentive soil.
Like most members of the rose family, Gillenia species are insect-pollinated, and are a useful provider of resources for insects in shady conditions.