To reach one of my favourite wildflower locations, I must climb down a steep embankment on which many tall weeds grow.  I have tripped more times than I care to remember during the descent, due to the fact that the strong stems of Field Bindweed have entangled the stems of other plants to produce an impenetrable maze.  The image above shows the Bindweed’s vine spiraling counterclockwise up a plant stem in search of sunlight.  (Note that although the vine is strong, it is not able to support itself.  For this reason, most of the images in the article were obtained with the plant hanging upside-down from a clamp.  The images were then inverted.  This technique occasionally produces anomalies such as the leaves seemingly angling up, rather than horizontally as in the image above.)

More than one Bindweed vine may encircle a stem, as can be seen in the image below.  Field Bindweed, sometimes called “Creeping Jenny”, forms a network of underground runners with shoots rising above the surface every four or five centimetres.  It can therefore produce huge patches which are really just one plant.  The taproot of a mature specimen can be from six to nine metres in length - try pulling up a Field Bindweed plant by the root!  Amazingly, these plants may live up to 50 years!

Field Bindweed blooms are about 2.5 centimetres in diameter, and are usually white with pink colourations.  All flowers of a particular plant (i.e. within a patch) have the identical colouration pattern. 

At the base of each funnel-shaped flower, there are five very small (5 mm), green sepals (modified leaves).

Up close, the blooms are quite beautiful.  They consist of five fused petals which form what is referred to as the funnel-like corolla.  The flowers have five stamens (the male pollen producing organs) of unequal length, and two thread-like white stigmas (the female pollen accepting organs).

A close-up reveals white, dust-like pollen grains adhering to the dark brown surface of one of the anthers.

The labelled image below shows the reproductive parts of the flower.  (The filament is the supporting structure of an anther.)

Under the microscope, the details of an anther and supporting filament are revealed.

A more highly magnified view of the anther’s surface shows some adhering pollen grains.

As can be seen in the image to the right, pollen grains stick to each other, as well as to the anther’s surface.

The three images that follow show the football shape of each grain, as well as the longitudinal grooves that are present on the surface.

Each of the two stigmas is covered with projecting lobes that help trap pollen grains transferred to it by the wind or insects.

Two flower buds at different stages of development are shown in the image below.

Field Bindweed has distinctive arrow-shaped leaves.

The final two photographs reveal the origin of the scientific name for this plant.  The genus name Convolvulus refers to the spiraling intertwined stems that provide support for the plant, while the species name arvensis means “of the field”.

Field Bindweed is ubiquitous.  Depending on your point of view, this may be a fortunate or distressing fact of life.  For me, the carpets of pretty pink flowers among the weeds are a definite plus!



Photographic Equipment

The photographs in the article were taken with an eight megapixel Sony CyberShot DSC-F 828 equipped with achromatic close-up lenses (Nikon 5T, 6T, Sony VCL-M3358, and shorter focal length achromat) used singly or in combination. The lenses screw into the 58 mm filter threads of the camera lens.  (These produce a magnification of from 0.5X to 10X for a 4x6 inch image.)  Still higher magnifications were obtained by using a macro coupler (which has two male threads) to attach a reversed 50 mm focal length f 1.4 Olympus SLR lens to the F 828.  (The magnification here is about 14X for a 4x6 inch image.) The photomicrographs were taken with a Leitz SM-Pol microscope (using a dark ground condenser), and the Coolpix 4500.  


References

The following references have been found to be valuable in the identification of wildflowers, and they are also a good source of information about them.

• Dickinson, Timothy, et al. 2004. The ROM Field Guide to Wildflowers of Ontario.  Royal Ontario Museum & McClelland and Stewart Ltd, Toronto, Canada.

• Thieret, John W. et al. National Audubon Society Field Guide to North American Wildflowers - Eastern Region. 2002.  Alfred A. Knopf, Inc. (Chanticleer Press, Inc. New York)

• Kershaw, Linda. 2002. Ontario Wildflowers.  Lone Pine Publishing, Edmonton, Alberta,Canada.

• Royer, France and Dickinson, Richard.  1999.  Weeds of Canada.  University of Alberta Press and Lone Pine Publishing, Edmonton, Alberta, Canada.

• Crockett, Lawrence, J. 2003.  A Field Guide to Weeds  (Based on Wildly Successful Plants, 1977)  Sterling Publishing Company, Inc.  New York, NY.

• Mathews, Schuyler F.  2003.  A Field Guide to Wildflowers  (Adapted from Field Book of American Wildflowers, 1902), Sterling Publishing Company, Inc.  New York, NY.

• Barker, Joan.  2004.  The Encyclopedia of North American Wildflowers.  Parragon Publishing, Bath, UK.

A Flower Garden of Macroscopic Delights

A complete graphical index of all of my flower articles can be found here.


The Colourful World of Chemical Crystals

A complete graphical index of all of my crystal articles can be found here.