Great topic. Right now I am reading Canadian Battles by Norman S. Leach and The Sacred Stones by Mattew Reilly.
I also like to read Minette Walters, PD James, Martha Grimes, and Elizabeth George who are British authors or in the case of Martha Grimes, write British mysteries. Peter Robinson is another favorite, he now lives in Canada.
Slade is at the top of my list of favorite Canadian authors. William Deverell, Alastair MacLeod, Kathy Reichs, and Jane Urquhart are other must reads for me.
On my list of must-read US authors are Harlan Coben, Nelson DeMille, William Diehl, Jeffrey Deaver, Tony Hillerman, Dana Stabenow, Douglas Preston & Lincoln Child, Michael Crichton, and John Grisham.
I have had a life-long interest in botany though from an amateurs veiwpoint. When I moved to the Cariboo some twenty odd years ago, I decided to learn everything I could about the native plants in our area which meant I also had to learn about all the plants that are not native to the area. I have an extensive library devoted to plants, their origins and identification, uses for medicinal purposes, for food use, and for other purposes such as dyes or in making twines.