Perennial of the Rosaceae family, Aruncus aethusifolius is native to Korea and Japan, where it grows in cool, shaded undergrowth, as well as on humid slopes and stream banks at altitude. It is the smallest species of the genus, very distinct from its large cousin Aruncus dioicus by its size and general appearance.
It forms a dense and compact tuft, 20 to 30 cm in height, with a rounded and well-ordered habit. The foliage is remarkably fine: the leaves, bi- to tripinnate, with narrowly cut and toothed leaflets, resemble those of Aegopodium or certain Aethusa, hence its epithet. A bright and shiny green in spring, this foliage takes on orange to red-coppery hues in autumn, which is one of its most unexpected assets for a plant of this size.
The flowers, creamy white, are gathered in small, upright, feathery spikes, elegant and airy, borne above the foliage. In its natural habitat, its flowering extends from June to July. In cultivation, it generally occurs in June, sometimes as early as the end of May depending on the climate.
It prefers cool, humus-rich, well-drained soil, in shade or partial shade. It does not tolerate prolonged drought. Its small size makes it a plant of choice for shaded rock gardens, woodland gardens, and container compositions.