Mr. Sibley with Sweet Bay Magnolia Fruit 
Bur Oak
Linden
Sawtooth Oak Acorn
Bur Oak Leaves
Fruit Laden Linden Branches
Fringe Tree Fruit
Pin Oak
Swamp White Oak
Sweet Gum Leaves
I was really excited to see that the author of the Sibley Guide to Trees, David Sibley was leading a walk in Fairmount Park as part of the author events for the Philadelphia Free Library. After meeting at the Recreation center at the start of Boathouse Row we walked into the Azalea Garden and he showed us the ways you can look at acorns and other fruit, branch direction, leaf shape, bark texture, overall tree shape and leaf arrangement to determine what tree you're looking at. We stopped at about 10 trees including a Bur Oak, Swamp Bay Magnolia, Red Oak, Linden, Ginko and Kentucky Coffee Tree.
I was amazed to find out he paints every illustration in his books and he still does not consider himself an expert in trees, despite working on this guide for 7 years. His bird guides he painted in gouache, but he found that impossible to use when painting lights and darks in trees, so he had to teach himself how to use acrylics for this book.
There was a big group of people on the walk and I was the youngest member by 30 years until a group of three college aged girls showed up. There were two actresses at the event, maybe they are filming some movie locally? but the rest of the group were birders and nature lovers (why are they all so old?).
