Wild Flowers come in a variety of shapes, colors, and sizes, variously arranged on the plant stem and with or without odors - some sweet, some not so sweet. Why are flowers so varied? What is the function of all this variation? Observation of flowers and their visitors over many years by naturalists in the ninteenth and twentieth century led to the formation of classes of flowers and pollinators called "plant pollinator syn-dromes."

While these syndromes overly simplify these complex relationships, they are nevertheless useful in organizinig plant characteristics associated with groups of pollinators. These syndromes are listed below for the major pollinator groups. Keep in mind that rarely will one flower species exhibit all, or even most, characters. In addition, many species will be more generalized, incorporating characteristics which may bridge more than one pollinator group. True evaluation of pollinator importance can only be made with proper observation and sometimes only with experimental work.

silhouttes adapted from Grant & Grant Flower Pollination in the Phlox Family

SOME DEFINITIONS:

Actinomorphic Flower - radially symmetric flower

Alternation of Generations - Life cycle characteristic in which a plant organism with two sets of chromosomes, the sporophyte, alternates with a plant organism with one set of chromosomes, the gametophyte

Angiosperm - The Flowering Plants, Division of Plants characterized with the flower as a reproductive unit, double fertilization, a more complex vascular system

Anther - site of meiosis, or reduction division, in the flower where pollen (the male gametophyte) is formed

Anthesis - anthers releasing pollen - the time of pollen release

Chasmogamous Flower - showy, animal pollinated flower

Cleistogamous Flower - closed, non-showy selfing flower - never opens

Cross Pollination - pollination between two different genotypes

Dioecy - male and female flowers on separate plants

Diploid - two sets of chromosomes - the sporophytic generation

Embryo sac - the female gametophyte

Fertilization - the union of the egg and sperm

Gametes - the egg and sperm produced by the gametophyte

Gametophyte - mature plant with one set of chromosomes

Haploid - one set of chromosomes - the gametophytic generation

Hermaphroditic - primitive condition in angiosperms, male and female function within the same flower

Heterostyly - two flower forms, one with long styles, one with short styles that are cross compatible between forms and cross incompatible within forms

Illegitimate Pollen - pollen either from self pollinations in a self-incompatible plant or from pollen of another species - inter-specific pollen that cannot germinate on the stigma or grow through the style

Incompatibility - failure of the pollen grain to either germinate on the stigma or grow through the style

Self Incompatibility - incompatibility to pollen of the same genotype
Cross Incompatibility - incompatibility to pollen from different species

Monoecy - male and female flowers separate in the same plant

Petals - whorl of colorful derived leaves involved in attraction (collectively known as the corolla)

Pistil - female portion of flower made up of stigma, style, and ovary

Pollen grain - male gametophyte that carries the sperm nucleus to the female gametophyte

Pollen vector - abiotic or biotic elements that effectively move pollen from one plant to another - wind, water, or animals

Pollination - the transfer of the pollen grain, the male gametophyte, to the stigma of the pistil of the flower

Pollinia - specialized pollen bearing sac found in the Milkweed and Orchid families

Protandry - anthers dehisce first within a flower (male first)

Protogyny - stigma is receptive first within a flower (female first)

Self Pollination - pollination within the same genotype

Sepals - outer whorl, usually protective "leaves," sometimes also "petaloid" and showy for attraction, collectively known as the calyx

Spore - product of meiosis, or reduction division, in the sporophyte that germinates and develops into the gametophyte

Sporophyte - mature diploid plant with two sets of chromosomes

Stamen - male part of the flower made up of the pollen producing anther and its stalk, or filament

Stigma - receptive part of the pistil of the flower

Stigmatic Clogging - when illegitimate pollen blocks germination sites for legitimate pollen

Zygomorphic Flower - bilaterally symmetrical flower

Zygote - the first product of the union of egg and sperm that will develop into the embryo within the seed

From Section 11315 Pollinator Protection Act of 2007

(b) Congress finds:

* many of the crops that humans and livestock consume rely on pollinators for healthy growth;

* pollination by honey and native bees adds more than $18,000,000,000 annually to the value of United States crops;

* 1/3 of the food supply of the United States depends on bee pollination, which makes the management and protection of pollinators an issue of paramount importance to the security of the United States food supply system;

* colony collapse disorder is the name that has been given to the latest die-off of honey bee colonies, exacerbating the continual decline of pollinators in North America;

* honey bee colonies in more than 23 states have been affected by colony collapse disorder;

* if the current rate of decline continues, the United States will be forced to rely more heavily on imported foods, which will destabilize the food security of the United States through adverse affects on the availability, price, and quality of the many fruits, vegetables, and other products that depend on animal pollination; and

* enhanced funding for research on honey bees, native bees, parasites, pathogens, toxins, and other environmental factors affecting bees and pollination of cultivated and wild plants will result in methods of response to colony collapse disorder and other factors causing the decline of pollinators in North America.

Pollinator Gardening: Pollinator Conservation Handbook

For Further Reading:

Barth, Friedrich G. 1985. Insects and Flowers the Biology of a Partnership. Princeton University Press, Princeton, NJ. (great detail on insect senses and behavior with relation to pollination)

Buchmann, Stephen L. and Gary Paul Nabhan. 1996. The Forgotten Pollinators. Island Press, Washington, DC. (a good overview of the previous 15 years of pollination ecology emphasizing community studies and conservation issues)

Grant, Verne and Karen A. Grant. 1965. Flower Pollination in the Phlox Family. Columbia University Press, New York. (a wonderful look at diversification in one flowering plant family)

Grant, Karen A. and Verne Grant. 1968. Hummingbirds & Their Flowers. Columbia University Press, New York. (a closer look at flowers visited by one pollinator group)

Heinrich, Bernd, 1979. Bumblebee Economics. Harvard University Press. (a fascinating accouont of the economics of foraging and its relationship to pollination; a great synopsis of the Bumblebee life cycle; and overall perspective from the Bumblebee point of view)

Meeuse, B.J.D. 1961. The Story of Pollination. The Ronald Press Co., New York. (Anecdotal and fun!)

Meeuse, B.J.D. and Sean Morris. 1984. The Sex Lives of Flowers. Oxford Scientific Films Ltd. (put together for film, a wonderful look at some of the exotic pollination mechanisms)

Proctor, Michael., Peter Yeo & Andrew Lack. 1996. The Natural History of Pollination. Timber Press, Inc., Portland. (for detailed descriptions of pollinators and their flowers)

Shepherd, Matthew et al.. 2003. Pollinator Conservation Handbook. The Xerces Society Portland Oregon. (emphasis on the conservaton of insect pollinators in NA)

Waser, Nickolas M. and Jeff Lllerton. 2006. Plant-Pollinator Interactons: from Specialization to Generalization. University of Chicago Press, Chicago.(up to date academic overview of pollination ecology)

Web Site Resources:

XERCES.ORG - international nonprofit organization dedicated to protecting biological diversity through invertebrate, including pollinator, conservation - includes specific fact sheets on pollinator gardening, pollinators and agriculture, and individual stories of pollination.

COEVOLUTION.ORG - The Coevolution Institute, a non-profit organization with the mission to catalyze stewardship of biodiversity

NAPPC.ORG - North American Pollinator Protection Campaign with the mission to encourage the health of resident and migratory pollinating animals in North America

POLLINATOR.ORG - The Pollinator Partnership sponsored by the North American Pollinator Protection Campaign and the Coevolution Institute dedicated to education about the importance of pollinators - an impressive listing of resources including a pollinator curriculum for grades 3-6