2 i Flora Unveiled
Among early Christians, flowers inspired a sense of piety and spiritual immanence,
embodying the union of the earthly and the divine. From the Middle Ages onward,
flowers have served as symbols of the core mystery in Christianity: the Virgin who
gives birth miraculously to the divine child. Throughout the Middle Ages and the
Renaissance, the lily appears almost as regularly as the angel Gabriel in paintings of the
Annunciation. In Dante’s Paradiso, a mystic white rose becomes a symbol of the poet’s
pure and unconsummated love for Beatrice, the paragon of female beauty and virtue. In
Dante’s rose, the divine light of the sun becomes material, and earthly love and divine
love become one.
Gabriel and Dante notwithstanding, the reputations of lilies and roses for virginity are
entirely undeserved. “Virgin birth” can and does occur in some flowers (it is called “parthe-
nogenesis”), but it is relatively rare. Nearly always, sex is involved, although not of the carnal
sort associated with animals. Pollination, not copulation, is the vehicle for sexual union in
plants.
The essential elements of pollination are quite simple. Pollen grains the size of dust
particles are released by the stamens of a f lower and find their way— usually with the
help of wind, insects, or other animal agents— to the upper surface of the pistil of
another f lower. There they germinate, forming a thread- like tube that grows down
through the neck of the pistil and emerges in the hollow base called the ovary. The pol-
len tube next empties its cargo of two sperm cells into a future seed, called the ovule.
The sperm cells enter the embryo sac inside the ovule, and one of the sperm cells fuses
with the egg, a process called fertilization. Voila! The first cell of the new embryonic
plant is born. This, in broad strokes, is what happens during sexual encounters of the
f loral kind.
As familiar as this basic description of plant sex may seem, the biological role of pollen
in plant reproduction is still widely misunderstood. This point was first driven home to
us when we came across a newspaper article about a survey given to visitors to the new
Pollinarium Exhibit at the National Zoo in Washington, DC. The purpose of the exhibit
was to educate the public about the function of flowers in sexual reproduction and the role
of insects in bringing about pollination. Before the exhibit opened, 100 visitors to the zoo
were interviewed to determine what they knew about pollination. When asked to define
pollen in the pre- exhibit interview, about 70% of those surveyed failed to connect pollen
with sexual reproduction in plants. After the exhibit had opened, the same survey was
repeated with a different set of 100 visitors. The post- exhibit interviews were conducted
just outside the exit door of the Pollinarium.^4 Once again, 70% of those surveyed failed to
connect pollen with sexual reproduction in plants. In other words, there was zero improve-
ment in visitors’ understanding of the sexual role of pollen after viewing the pollinarium
exhibit.
Intrigued by the results of the poll, we decided to visit the Pollinarium to evaluate its
effectiveness first- hand. The exhibit was housed in a small tropical greenhouse attached to
the Invertebrate Building. We arrived on a cold rainy day in December. Upon entering the
muggy warmth of the greenhouse, we were immediately surrounded by hundreds of flut-
tering, iridescent butterflies, flitting delicately from flower to flower and from shoulder to
shoulder, oblivious of their human observers. It was as if we had walked straight into a