In wooded areas across North America, a spring walk in the forest means seeing trillium (Trillium spp.), also called wakerobin, in bloom. In a family all their own, the Trilliaceae, they are native to North America and Asia. Eight species occur in western North America, 35 in eastern North America and six species in Asia. Showy flowers can be white, pink, red, yellow or speckled, and appear in early spring before forest trees leaf out.
Trillium is a three-parted plant -- three leaves come from the same point on the stem. Flowers have three sepals and three petals. There are two trillium types, based on how the flower grows. Sessile trillium has flowers that rest directly against green leaves. Pedunculate trillium has stalked flowers held above mottled or spotted leaves. The perennial plants grow each spring from underground rhizomes. After flowering, the leaves remain for a while to replenish the rhizome's food supply before going dormant. Trillium is not meant for a cut flower; if you pick the flowering stalk, the underground rhizome won't get the food it needs after blooming and it dies.
Large-flowered trillium (Trillium grandiflorum) has 3-inch-wide white flowers that fade to pink, and go from cup-shaped to open with age. Plants are 1 to 3 feet tall and form clumps over time. It has a double-flowered form, "Flore Pleno," that looks like a gardenia. Musk-scented flowers of Pacific trillium (Trillium ovatum) grows about 1-1/2 feet tall, with narrower leaves than large-flowered trillium and a white flowers turning pink. Both species grow well in U.S. Department of Agriculture hardiness zones 5 through 8.
Deep red flowers almost 4 inches wide, the largest in the genus, grace the 2-foot stalks of sweet Beth (Trillium vaseyi). Flowers appear just below the leaves in mid- to late spring in USDA zones 5 through 8. Red trillium (Trillium erectum) bears upright chocolate or reddish-purple flowers that have an unpleasant scent detectable at close range. The fragrance attracts pollinating flies. Plants are 14 to 20 inches tall, growing in USDA zones 4 through 9.
The sessile, yellow flowers of yellow trillium (Trillium luteum) have a faint fragrance of lemon oil and sit atop large green leaves mottled with silvery-green. Plants grow 14 inches tall in USDA zones 5 through 7. Little sweet Betsy (Trillium cuneatum) has variably colored sessile flowers, ranging from yellow to green, brown and maroon. It is the largest of the eastern sessile trilliums, with silvery mottled leaves, and is hardy in USDA zones 6 through 9.