Reddit reviews Economic Botany: Plants in our World

One of the most interesting courses I ever took was on economic botany. We discussed the relationships between many of the fruits and vegetables that we normally eat.

Did you know, for example, that broccoli, cauliflower, brussels sprouts, cabbage, kale, collard greens, and kohlrabi are all the same species?

The professor who taught the course also wrote the book, if you're interested in learning more. Otherwise, I'd go on Wikipedia (or their taxonomy site) and notice the taxonomy of the fruits you're curious about. That way you can get an idea of how closely they're related.

Here's the book:
http://www.amazon.com/Economic-Botany-Plants-our-World/dp/0072909382

If you are interested in Botanical Terminology (in terms of identification) I would recommend Plant Identification Terminology An Illustrated Glossary which you can get for fairly cheap off of Amazon. Any Peterson Field Guide in regards to plants would also be good as they have good descriptions and pictures. I'd say that learning to identify plants is just as important as learning about how they work. I'll edit this post later, however, to post a few plant biology
books I've read that you might be interested in.

EDIT:

• Economic Botany is an interesting textbook. It deals with the more cultural aspects of botany as it describes how different cultures use plants. The first chapter is a brief primer on the basics of botany which is enough to understand the terminology, naming conventions, and inner workings of the plants mentioned. It's not an easy read but it isn't too dry either.
  
  
• Botany is a good botany textbook. It, again, isn't an easy read while still being interesting. The only thing I would note about this book was that it was published in 1995 so it while not contain any of the newer theories that u/Shilo788 talked about. Other than that I'd say the material within it is fairly up to date and is a good introduction to botany.