Leaf color is mainly one of the hues of red including mahogany, rust, and purple except for the deeper bronze (with brown hues).
Caladium corms are tropical plants grown for their summer foliage, however they do send up an arum type flower (a member of the Araceae family). Foliage comes in many different variegation patterns in red, pink and white. There are a over a thousand cultivars, most from the Caladium bicolor species. Plant bulbs after May 1st, only about 3 inch deep. Caladiums like it hot and moist. Complete shade works OK, or morning sun only.There are a few sun tolerant cultivars available. For larger leaves.
Heucheras are native to the North American continent and make wonderful foliage and flower plants for your woodland border. Grown mostly for its interesting, evergreen foliage, coral bells will continue to flower on mature plants if kept deadheaded into the summer. Although the native heucheras are great in themselves, there are hundreds of hybrid cultivars to choose from.
The most remarkable quality of Red Dragon Persicaria is its burgundy red patterned leaves and red stems, a plant grown much more for its foliage than flowers. (The flower stalk in the upper right is of Acanthus spinosus.) Not a native (native to China) it will come back if nipped by a late frost and will suffer sunburn in afternoon sun. Red Dragon may take 3 years before flowering, however, that is not a drawback.
There are many different sedum species and varieties of this delightful spreading groundcover. I took this picture on a garden tour in Angel Fire New Mexico, and have not been able to identify it yet. It is easy to see from the picture how it got its common name, stonecrop. Sedum groundcovers spread nicely in a low to medium water use area of gritty, well drained soil, and will do just fine in afternoon shade.
Switchgrass is one of the best native ornamental grasses of our tall prairies. Switchgrass forms upright bunches of wide 1/2 inch green blades, with open pale purple inflorescence arising another 2 feet in late summer to fall. Switchgrass will thrive with every other week supplemental irrigation. There are many varieties of switchgrass, 'Prairie Sky' is the most drought tolerant (low, xeric) with blue blades. Other fine selections are 'Heavy Metal' with metallic lavender blue foliage turning reddish towards fall, and 'Shenandoah' with leaf blades tipped in red.
Mahonia repans is one of my favorite plants with four seasons of interest. Low growing and spreading evergreen shrub is native throughout the Rocky Mountains. Bright yellow berries in spring are followed by black berries in summer and reddish winter foliage. The leaves are thick, glossy and holly shaped. Creeping Oregon grape holly prefers amended, humusy soil that replicates its native habitat as an understory plant in woodlands, but is low water-use once established. It will spread to cover an area, but not invasive. Very attractive!
Oregon grape holly is an evergreen holly-like shrub native to the Pacific Northwest Rockies down into California. Upright, it is slow growing but can reach a height of 8 feet. Best when grown in shade, especially out of afternoon sun. Prefers a more humusy soil but will only required once a month watering when established, however, can also be placed in medium and high water-use areas. Bright yellow flowers in spring, followed by dark blue berries in summer. The thick, glossy, holly-like leaves have spines at the points. Leaves turn from green to red in winter.