Thirteen years ago, the author taught a correspondence course to 20 high school students across the country while taking classes in environmental studies at a nearby college. What he learned, from his far-flung students as well as those leaves and trees, is that when it comes to writing — and studying plants — one thing matters most, the attention to detail. The author wanted to be one of those who could teach writing through the mail, who was so clear in his own use of language that the kids couldn't help but learn to write, to burn with a passion to write, once he was through with them.