Figure 1-12:

Resin nodules on a female Cannabis sativa flower ("bud").
These sticky, globular secretions have the greatest concentrations
of the marijuana drug.  (Photo from Magnifications.  Copyright © 1977 by David Scharf.
Reprinted by permission of Schocken Books, published by Pantheon Books, a
Division of Random House, Inc. and Century Hutchinson, London.)