Genus & species?  Without using Google?  Yeah, right.   
  I had the strangest experience of my higher ed years with dendrology class.  Course is divided into 2 portions ... 1st semester is tree focused & 2nd semester is focused on lumber.  1st attempt was quickly apparent that I was not "getting it".  Dropped the course after about a month and seriously considered changing majors.  Following year took the course ... had a ball and grades were 1st rate.
Thanks, fellas, for the help!