Asarum canadense (American Ginger), with its large, heart-shaped leaves, is ideal for the woodland garden, and why wouldn't it be?  It's home to this native wildflower, and American Ginger makes a lovely ground cover in the cool shade of a woodland setting.  If the large, heart-shaped leaves are not enough to sway you, Asarum canadense also delights with cup-shaped, maroon flowers and roots that can be used as a ginger substitute.  Not many plants can boast of so many attributes.  Zones 4-8.  Quarts. (Photo attributed to Chris S. Packard, GNU Free Documentation License, Wiki Commons)