The Dock Is In.

Prairie dock, compass plant's more popular (probably) sibling, blooms above the prairie. With its huge -- often well over a foot in length and width -- leaves, this plant distinguishes itself from the typical prairie dwellers. Living in bright sun, wind, and in dry soils, many plants in the prairie have small, narrow leaves. This makes sense, right? Big leaves are necessary to get a lot of sun, but this isn't a problem in the prairie -- sun is plentiful. And big leaves require hydration -- but water isn't as available. The silphium species break that rule, but are well-adapted to do so. The leaves tend to orient themselves in a north-south way to avoid getting the direct sunlight. (This is how compass plant gets its common name, but dock does the same thing). And prairie dock has a natural coolant. On a hot summer day, if you touch the leaves -- after you get over how thick and scratchy they are -- you'll notice that their coolth. I have heard that pioneers would pick a leaf on hot days and put it under their hats as a sort of personal air conditioning! And of course, they have long roots, with a thick sturdy taproot that penetrates the depths of the soil.
These pictures were taken at school. In my yard, I have 3 or 4 prairie dock plants, which come back every year for the past few years, and some have the full sized leaves that one would expect on a prairie dock... but I have never gotten a flowerstalk (which is too bad because they're smooth and reddish and pretty even before they yellow flowers open). I must have an area that's too good to kill them, but not good enough for them to be truly happy. Oh, well.