The Quandary Over Plant Sex j 33 3
tropical rainforest, vibrant with beating life. A large color poster made it abundantly clear
what the exhibit was about. It read:PLANT SEX?
Birds do it, bees do it, and even flowers and trees do it!No punches pulled here. The body of the poster included a clearly drawn life cycle of a straw-
berry plant and a picture of a butterfly in the act of pollinating a flower. The process of pollina-
tion was clearly and simply explained. It seemed to us that the message that pollen is involved
in plant sexual reproduction came across loud and clear. But the clarity of the message was
not reflected in the Pollinarium survey. Taken at face value, the survey suggests that, however
technologically sophisticated the average person may be when it comes to using the latest digi-
tal device, he or she still has a very limited understanding of the fundamental biological prin-
ciple of the sexual role of pollen in plant reproduction. A disheartening number of people in
the survey understood the function of flowers much as the ancients did, as beautiful, colorful,
fragrant adornments, whereas pollen was perceived in negative terms as the cause of allergies.^5
We wondered, is pollination— that crucial step in the sexual reproduction of all seed-
producing plants— such an arcane, esoteric phenomenon that most people have either never
heard of it or find too difficult to comprehend? Thinking about this question, we began to
suspect that the problem was not so much one of education as a subjective bias that most
people have, and perhaps have always had, about plants. If people tend to view plants as
inherently asexual, if they think of sexuality as somehow incompatible with the very nature
of plants, it would take far more than a casual stroll through the Pollinarium Exhibit to chal-
lenge their preconceptions.
The Pollinarium survey was much too small to be statistically significant and may not accu-
rately reflect the average zoo- goer’s true understanding of how plants reproduce. On the other
hand, there is historical precedent for the apparent ignorance about plant sexuality reflected in
the survey. Historians of science have long marveled at the extraordinarily long delay before sex
in plants was discovered at the end of the seventeenth century. This delay is all the more remark-
able when one considers that sex in animals was probably discovered around 14,000 years ago,
when dogs were first domesticated and bred. Thus, a span of more than 13,000 years separates
the discovery of sex in animals and plants, even though humans have depended on plants and
agriculture for their survival for at least 10,000 years. Equally astonishing, after the new sexual
theory was first proposed by the British physician Nehemiah Grew in 1684, it was summarily
rejected by some of the leading botanical lights of the day, and it continued to be challenged
on philosophical, moral, and religious grounds for another 150 years until the middle of the
nineteenth century! Perhaps the apparent resistance to the idea of sex in plants suggested by
the Pollinarium survey has its roots in something deep within the human psyche, an ancient
prejudice rooted in “common sense” going back to prehistoric times.
A well- known example of how an entrenched bias based on common sense can block
scientific discovery is the delayed acceptance of the heliocentric model of the solar system.
Aristarchus of Samos, a Pythagorean astronomer who lived in the third century bce was the
first to postulate that the Earth revolved in a circular orbit around the sun, but the theory
failed to take hold because it violated common sense. Instead, the geocentric Ptolemaic system