The Compass Plant

Yesterday I went on a ecological tour of the St. Olaf campus. They claim to be one of the "greener" campuses. I think they wanted to keep the parents busy so the kids could unpack. I saw the new wind turbine on campus. The turbine provides energy to the campus and sells some energy to the Northfield power grid. I was surprised by how much noise it makes. I have never been that close to a turbine before and I assumed they would be silent. I could hear the wind whistling through the blades. Each blade is hollow. The part of the blade where it joins the hub is large enough for a 6 foot tall person to walk through. Even though the three blades were slowly rotating, the tips of the blade go 186 mph. The wind turbine turns at wind speeds between 10 and 58 mph. It shuts down when the wind goes faster than 58 mph because it would be unsafe. The turbine rotates to face the wind. We walked through the prairie near the compost area. They compost the leftover food. That smell was nasty! Walking through the prairie, our guides showed us bluestem grass, Canadian rye grass, and several examples of the compass plant. I had never heard of a compass plant before. The leaves of the plant are a little thick but flat and prickly - sort of like a super thin cactus leaf. The leaves arrange themselves north and south so that one side of the leaf catches the morning sun and the other side of the leaf catches the afternoon sun. The north/south accuracy is greater in the spring. By late summer, the wind has twisted the plant around. Some of the compass plants get to be 5 or 6 feet tall. The flowers were all dried up and brown but you can see by the picture that they are yellow. The flowers resemble sunflowers. The roots go down as far as 10 feet into the soil. I think it is fascinating how plants move toward the sun. I think compass plants and sunflowers blur the line between plants and animals. Plants by definition are not supposed to have voluntary motion or locomotion.