To get the experience of a PDF install, you need the correct reader:
It explains why plants evolved certain traits, rather than just asking you to memorize them. To get the experience of a PDF install,
If you absolutely cannot afford the $80–$120, consider renting the e-text from Amazon (30–180 days) or buying a used 6th edition (still 80% relevant) for $20. To get the experience of a PDF install,