More wintry weather for us tonight and tomorrow. While we wait for new spring leaves, here are some more leaves from my yard last fall.
1. Tar spot looks like tar on the leaf, but is caused by a fungus, Rhytisma acerinum. This is an endophytic fungus: it lives inside of the cells of the leaves that it feeds on, without really causing much damage. See this paper
2. Don’t maples have a nice star shape? Japanese maples are particularly nice, but of our native American maples, I really like the shape of these silver maple. Check out this highly mathy article on leaf shapes.
3. I’m not sure what has caused these spots on the stems. (Remember from an earlier post that these stems are called petioles.) At the spot on the right there appears to be an incision in the leaf, perhaps made by an insect for deposition of it’s eggs?