Plant of the Week: Compass Plant

Before GPS, the compass plant (Silphium laciniatum) was an early Iowan’s means of navigation. This perennial prairie plant, reaching skyward in a single stalk as high as twelve feet, is a unique addition to Iowa’s native grassland. Leaves with finger-like extensions and many bright yellow flowers distinguish the compass plant from its many neighbors. However, the most fascinating quality is a compass orientation which gives the plant its name. Leaves of the compass plant, when mature, align on a north-south plane such that the flat surfaces face east and west. This technique minimizes solar radiation, as the sun will not shine directly on the leaves throughout most of the day. Additionally, this pattern of growth allows the plant to use water as efficiently as possible, maximizing carbon gain. In short, the compass plant points itself in the direction of success. When the north star isn’t out, use this awesome organism to guide your way.