First Lessons in Nature Study by Edith M. Patch (1926)
This excellent book is just about to turn 100! My 4th grade daughter and I are halfway through it, for one of our homeschool science books this year. We absolutely love it! Miss G will thoughtfully answer the comments and questions of the author as I read the chapters out loud to her. (That's one of my tests for non-fiction read-alouds, and this one passes all tests with flying colors!). Don't think that it can't be a useful book because of its age--I myself have learned so much from it about plant and animal families that I never knew, information which never expires.
This truly is a "Living Book," written in a lively conversational style that doesn't talk down to students, but lifts them up to see things in nature in new ways.
I found a paper copy in a New England book shop this summer, and I am so glad I took a chance on it. I highly recommend printing out the PDF and using some, or all of it, with your elementary-aged students, if you can't nab a vintage copy yourself.
“If we are honest, we can still love what we are, we can find all the good there is to find, and we may find ways to enhance that good, and to find a new kind of living world which is appropriate for our time.” ― Christopher Alexander