I purchased this plant last year from Broken Silo Nursery in Michigan as Callianthemum sp. Serowitz. This is likely to be Callianthemum anemonoides. Whatever the name this thing is cool and also the first time I have been successfully able to grow any Callianthemum. Despite their affinity for mountainous regions, this species demands a moist, woodsy soil, and shuns the rocky, drier soils suited to many other alpines. Admittedly I have only grown this in a container, but even i last year's heat it just kept on growing. Outside I would plant this in a raised bed with moisture retentive soil and morning sun. Hopefully it is self fertile and there will be some seedlings to experiment with in the future. This is a group of plants I would like to try more of!
To give and idea of size, this entire plant is growing in a 14 cm diameter container. The curiously swollen peduncle is interesting in it's own right.
The label is about 10 cm in length.