Astrantia favor quite damp conditions
Synonym: Porteranthus trifoliatus
I think best planted en masse in the front of a border or in a clump of 5-7 in a rock or gravel garden situation
More: Leaves and root have been used medicinally
According to The Ladybird Johnson Wildflower Center
Alnus serrulata - Smooth Alder carex Astrantia favor quite damp conditionsSizes available: #1 (Trade gallon), perhaps fall, 2026 Basics: zones 4 9, sun to part shade, 10 20 feet high at maturity, 8 15 foot wide canopy (multi stemmed, suckering), catkins bloom March to April, both male and female on same plant, cones develop. Wants moist wet mucky soil, but is okay with medium moisture, is clay tolerant, doesn't like a high pH. Common names: Smooth Alder, Hazel Alder, Tag Alder, Common Alder, Black Alder, Brookside Alder