Spring is moving north. One way we know that is to look at the early spring ephemeral wildflowers. These flowers are designed to leaf out, bloom, produce seeds, and then go dormant before the landscape becomes too shady. Some of them keep their leaves all summer, and some go dormant as the summer heat comes. Anyone who has spent much time in the woods during the spring will recognize a few of these flowers, but a couple may be new. There are about 40 species of Trilliums in North America. They probably have that many common names, including “wake robin,” “tri flower” and “birthwort.” Some are in only one or two states, and some are found just about everywhere. What most of us would call a “three-part leaf,” botanists call a “bract” because it is connected to the flower. The bract is often very attractively mottled with light and dark …