Tiarella trifoliata, commonly called threeleaf foamflower,<ref name=WTU>Template:Cite web</ref> laceflower,<ref name=GRIN>Template:GRIN</ref> or sugar-scoop,<ref name=GRIN/> is a dicot in the family Saxifragaceae.
The flowers are bell-shaped, white, solitary from an elongate, leafless panicle. The calyx lobes are 1.5–2.5 mm and petals are 3–4 mm. Basal leaves are 15–80 mm long and up to 120 mm wide, trifoliate or palmately 3- to 5-lobed. Cauline leaves are infrequent and much smaller.<ref name=WTU/>
There are three varieties of T. trifoliata:
- T. trifoliata var. trifoliata, which has leaves that are irregularly lobed, with coarse teeth.
- T. trifoliata var. unifoliata, which has simple leaves.
- T. trifoliata var. laciniata, which is confined in its range from Washington only as far north as Vancouver Island, and has deeply lobed leaves.<ref>Pojar, Jim; MacKinnon, Andy. Plants of the Pacific Northwest Coast. Lone Pine Publishing, 1994, p. 168, Template:ISBN</ref>