Flowers Increase Pollen Transfer

a blue and yellow wasp orchid is seen against a bright green blurry background

Biological Strategy

Wasp orchid

AskNature Team

Image: AJ Cann / Flickr / Some rights reserved

Send Chemical Signals (Odor, Taste, Etc.)

Tastes, odors, and hormones are all chemical signals that can float through the air or water, or be applied to solid surfaces. Chemicals are important for signaling and communication; even humans, with our underdeveloped sense of smell, are influenced by chemicals more than we realize. Chemical signals are often specific to the living system intended to receive them, and are often relatively weak, dispersing upon moving through liquids or gases. To ensure that chemical signals reach their target, living systems create unique chemical signals and methods of dispersal. One example is an orchid that is pollinated by dung beetles, and therefore distributes a dung-smelling aroma to attract them.

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Send Light Signals in the Visible Spectrum

The visible spectrum is the portion of the electromagnetic spectrum that the human eye can detect. Visible light can be thought of in two ways–light as illumination (such as that used by fireflies) and colors that result from light being absorbed or reflected. Living systems use light for a variety of purposes. Sometimes, they use it to make themselves highly visible (like a peacock showing off his brilliant feathers to a potential mate). Other times, they use it to become virtually invisible (like an owl hiding in plain sight when it rests during the day). When a living system sends a light signal, it must create that light or color in an energy- and material-efficient way. Living systems create and enhance color using such strategies as non-toxic pigments, structures that bend and absorb different wavelengths, and chemical processes that create bioluminescence.

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Distribute Solids

Solids include resources such as food, seeds, spores, and leaves, which living systems must sometimes move to accomplish various activities such as pollinating, feeding their young, or building shelters. To effectively distribute solids, living systems must use strategies appropriate to the sizes and types of solids and the media in which they exist (air, water, or another medium). This may entail strategies beyond simply holding and carrying solids. For example, some seeds are carried by the wind to new locations for germination. Others–like the burdock plant’s hooked seeds–cling to animal fur to be transported.

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Flowering Plants

Clade Angiosperms (“receptacle seed”): Dandelions, oaks, grasses, cacti, apples

With 416 families containing some 300,000 known species, angiosperms are the most diverse group of plants, and they can be found around the globe in a wide variety of habitats. They are characterized by seeds that grow enclosed in ovaries, which are enclosed in flowers. The floral organs then develop into fruits of myriad kinds and dimensions, from simple seed casings on maples to elaborate fleshy growths like papayas. The oldest flower known from fossils, Montsechia vidalii, appeared during the Jurassic Period 130 million years ago. They are the primary food source for herbivorous animals, which in turn makes them the indirect food source for carnivores as well.

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The flowers of some orchids increase efficiency of pollen transfer because they look or smell like female insects.

“While most flowering plants reward pollinators with tasty nectar, many
orchid species turn to trickery. Some use what’s called food deception.
They produce flowers that look or smell like they offer food, but offer
no edible reward. Other orchids use sexual deception. They produce
flowers that look or smell like female insects, usually bees or wasps.
Males are drawn to the sexy flowers and attempt to mate with it. In
doing so, they accidentally collect pollen on their bodies, which
fertilizes the next orchid they visit.

“…[Researchers] found that populations of sexually deceptive orchids had higher ‘pollen transport efficiency’ than the species with multiple
pollinators. In other words, a higher percentage of the pollen that was
taken from sexually deceptive orchids actually made it to another orchid
of the same species. The orchids with multiple pollinators had more
pollen taken from their flowers, but more of that pollen was lost —
dropped to the ground or deposited in flowers of the wrong species.” (Science Daily 2009)

http://www.journals.uchicago.edu/doi/abs/10.1086/648555?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%3Dncbi.nlm.nih.gov
http://www.sciencedaily.com/releases/2009/12/091217183442.htm

Last Updated August 18, 2016

References

Journal article

Pollination Efficiency and the Evolution of Specialized Deceptive Pollination Systems

The American Naturalist | 12/11/2009 | Giovanni Scopece, Salvatore Cozzolino, Steven D. Johnson, Florian P. Schiestl

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