In addition to the materials noted on the Clemson Herbarium website, the following resources may be useful:
The University of South Carolina A.C. Moore Herbarium. This herbarium is directed by Chief Curator Dr. John Nelson and Assistant Curator Herrick Brown.
Guide to Reading an Herbarium Specimen
A guide by Amy Blackwell to help interpret botanical vouchers.
The USDA Plants Database.
SERNEC (Southeast Regional Network of Expertise and Collections).