Happy Plants

Deals with Cleve Backster's experiments and other mind/plant experiments, including ones backing up Backster.
http://www2.cedarcrest.edu/academic/writing/pleasure09/wallflowers.htm

Chapter Six- Cleve Backster's Laboratory

A chapter in a web-based book by psychologist Ingo Swann. Deals with a trip made by Swann to Backster's laboratory and chronicles the first-hand experiment he witnessed.
http://www.biomindsuperpowers.com/Pages/RealStoryCh6.html

Subtle Energy

An article in a web-based magazine by Paul von Ward Lightworks. Deals with Cleve Backster's mind-plant discoveries and the author's speculations about them.
http://www.lightworks.com/MonthlyAspectarian/1998/May/0598-05.htm

Our Intelligent Companions, the Plants

Contains much information on various mind/plant type experiments throughout history. Some people mentioned include Cleve Backster and J. Chandra Bose.
http://www.theosophy-nw.org/theosnw/brother/br-jvmj2.htm

Vignettes From the History of Plant Morphology

Articles about people, mostly Agnes Arber, who created unconventional theories about plant morphology.
http://members.aol.com/cefield/hauke/contents.html

Plant Articles by Judith Handelsman

A series of articles from various magazines. The second one has relevance primary perception discoveries, as it describes Handelsman's own experiences with the phenomenon.
http://here-and-now.org/judith/articles.html

Sacrifice for Science

Contains some information on Cleve Backster's experiments and the author's interpretations of the implications.
http://www.hotguano.com/Tabari/otrhog/sacrifice.html

Dark Corner - Plants Feel

Offers information on how plants can read human minds.
http://www.angelfire.com/clone2/darkcorner/plantsfeel.html