Their main book will be Jeannie Fulbright's Exploring Creation With Botany. I've been wanting to try out one of these elementary-level texts since they came out, so when a copy of Botany came our way I decided to use it this year (and was pleased to find out that Coffeemama's children will be using the same book). Our family science bent tends towards physical rather than natural science, so learning some plant terminology will actually be something new (and, I hope, interesting).
We also have a basket of nature books and a shelf of how-things-work books, but I'm trying to pick out a couple of things for read-aloud times. I had been going to start with Rowena Farre's Seal Morning, but it's almost too close to the kind of book (Crystal Mountain) that we're doing for Travel, so I wanted something other than life-in-another-country, even if it does have a seal in it. We'll read it, just later on or next year. Right now I'm deciding between Grey Owl's Sajo and the Beaver People, and Clara Dillingham Pierson's Among the Forest People, online at The Baldwin Project. How could we not like a book that has this in its first chapter:
When Mr. Red Squirrel first came to the forest, he knew nothing of the way in which they do, and he afterward said that learning forest manners was even harder than running away from his old home. You see, Mr. Red Squirrel was born in the forest, but was carried away from there when he was only a baby. From that time until he was grown, he had never set claw upon a tree, and all he could see of the world he had seen by peeping through the bars of a cage. His cousins in the forest learned to frisk along the fence-tops and to jump from one swaying branch to another, but when this poor little fellow longed for a scamper he could only run around and around in a wire wheel that hummed as it turned, and this made him very dizzy.--Among the Forest PeopleSigh. But I do have to decide pretty soon. I think we might go for Mr. Red Squirrel.