Aruncus aethusifolius, a dwarf goat's beard, is a clump-forming perennial which typically grows to only 12" tall. Features fern-like, compound, 3-4 pinnate, dark green leaves which form a foliage mound to 4-6" tall. Astilbe-like plumes of tiny, creamy white flowers rise above the foliage to 12" tall in late spring. Zone 3.