Species-specific attraction of pollinators
is characteristic of many of the
more highly evolved species of orchids
(1). In those orchids the pollinating
agents isolate and prevent hybridization
between compatible populations. The
development of numerous species in
the orchid family (imore than 1i) percent
of all species of flowering plants
are orchids) can probably be attributed
in large part to the attraction of particuLlar
kinds of pollinators. Some of
the most bizarre pollination systems
known fuLnction in attraction of specific
pollinators: among them are food
and prey imitation, sexual deception.
and pseudoantagonism ( I). Generally,
the pollinators are attracted by means
of brightly colored flowers or strong
fragrances associated with the production
of nectar. Bees, butterflies, moths,
flies, and birds are the most common
kinds of orchid pollinators: bees predominate
(I). Much of the floral variation
of orchids is a result of morphological
rearrangements necessary to
accommodate the physical characteristics
of suLch diverse pollinating organisms.
Fra;Irance is often the dominant
means of attraction, particularly in
moth-pollinated floswers, wshich are
searched OuLt and visited at night. Many
bee- and fly-pollinated species of
orchids depend upon fragrance as an
attractant and then reinforce that stimulus
with flower colors and elaborate
strutctuLral arrangemients. Fragrances
nmay attract a broad spectruLm of