There are tall astilbes for herbaceous borders and small ones of rock garden stature, but all prefer cool and damp conditions. They are clump-forming perennials with branched spikes bearing a multitude of tiny flowers, usually pink or white, sometimes red, closely packed together into a fuzzy mass. The multiply divided leaves are also attractive, opening with bronze colouring, and the dried flowers stems can stand through the winter, adding structure for many extra months. See also Filipendula.

Astilbe rivularis is a species is usually described as having white flowers, so the description of this collection as yellow-green may just reflect their incomplete openness at the time of the observation. It is a typical Astilbe, with a great spire of tiny flowers, over sharply toothed leaves.