HarTree ID vocabulary, a lesson on an Evanston sidewalk.

People walking in the 2100 block of Hartrey Avenue late last week might have paused in the middle of the block to read several squares of informative sidewalk.

Nineteen-year-old Julie Freeman, a biology major at Earlham College, challenged walkers to identify the parkway trees on the east side of the street:

“There are more than 5 trees of 9 different types or species on this block alone,” between Noyes and Payne streets, she wrote. “Do you want to try identifying those trees? Don’t worry. I’ll give you some help.”