Oh dear, another addictive family of hardy herbaceous perennials! Lots of unusual species to choose from and some new breeding between them. Mostly tight clump formers with airy upright flowers in summer.
This is one of those genera of plants where a very small number are known by gardeners, and those are not the best plants in tha family. The more we investigate Thalictrum the more interesting, garden worthy, species and cultivars we find, and it is becoming apparent that others are at it too! On the whole they are a group of clump forming herbaceous perennials where the foliage is as interesting as the flowers, and where the flowers are often (usually?) without petals.
Thalictrum are typified by their divided, usually ferny foliage which is often greyish, the young foliage even blueish or purpleish. Stems are usually wiry, strong and upright, in many cases dark in contrast with the greyish foliage. Flowers range from yellow and creamy white, through pinks to the more common lavender, lilac and purple.
Most Thalictrum are perfectly hardy in the UK given drained, but ordinary soil in sun or perhaps light shade for some species.