Weeds of the Northeast by R.H. Uva and others
Here, at last, is a lavishly illustrated manual for ready identification of 299 common and economically important weeds in the region south to Virginia, north to Maine and southern Canada, and west to Wisconsin.

Armitage's Native Plants for North American Gardens
Whether you are a native plant enthusiast or simply wish to use plants that work in the landscape, you'll find everything you are looking for in this readable, information-packed volume.

The Jepson Manual: Higher Plants of California
First published in 1925, Willis Linn Jepson's Manual of the Flowering Plants of California has been a standard reference for teachers, students, and naturalists.