(This was originally supposed to go up this morning, but then I got concerned that it wasn't, you know, planty enough. Thus, the Papaver photo earlier.)
On 27 December, we woke up to a clear, sunny morning where everything that had been outside overnight had turned white. This is called rime (in this specific case, "hard" rime -- there is also a "soft" rime, but it's different), and occurs when fog forms at below-freezing temperatures, and is very pretty.
These pictures were taken in and near Hills, IA, just south of Iowa City.