A Close-up View of

"Tatarian Honeysuckle"


(Lonicera tatarica)


by Brian Johnston   (Canada)

THE WILD HONEYSUCKLE

Fair flower, that dost so comely grow,
Hid in this silent, dull retreat,
Untouched thy homed blossoms blow,
Unseen thy little branches greet:
No roving foot shall crush thee here,
No busy hand provoke a tear.
..................…

Philip Freneau (1752-1832)


Honeysuckle bushes are a common sight in southern Ontario where I live.  Most have flowers in shades of pink, but a few are white.  About five metres from the stream that passes through the area where I commonly search for wildflowers, a single straggly bush, hidden from passersby by trees, possesses the brilliant red blooms that can be seen above.  I suspect that the seed that grew into the mature plant was “dropped”, (need I say more?), by a bird perched on a branch of the tree that overhangs this particular bush.  The fruit, that will be seen later in the article, is a favourite food of birds, and small mammals.  The species is particularly cold tolerant, and thus survives our extremely cold winters.

Tatarian honeysuckle is sometimes referred to as ‘bush honeysuckle’, or ‘twinsisters’ (due to the fact that the blooms occur in pairs at the end of a stem.)  It originated in Southern Russia and Turkistan, and was first introduced into North America in the late eighteenth century.  Honeysuckles belong to the Caprifoliaceae family.  The name derives from the Latin caprifolium which roughly translates to “goat’s leaf”.  (Honeysuckle leaves were a favourite food of goats.)

As can be seen below, the bush from which the flowers were obtained, is almost completely surrounded by trees and saplings.



Notice in the image at right below, that the oval leaves are arranged opposite one another, and that the stems supporting the pairs of flowers grow from the points of intersection of the leaves to the stem, (the “axils”).



Beneath each pair of buds there are two leaflets. Immediately above the leaflets, there are two sepals (modified leaves) that partially cover each of the green, egg-shaped, immature ovaries.  At the top of each ovary is a ring of very tiny pointed, green, sepal-like structures.  Notice in the image at right, that the bottom surfaces of the lower-most leaflets are covered with small hairs.



The bud itself has an elongated red, bulbous top, and white tubular bottom.  It is just possible to discern the individual petals of the flower making up the topmost section of a bud.



A mature flower possesses five spoon-shaped, brilliant red petals.  Notice that the edge of each petal is white.



If one of the areas of intermediate colour is examined under the microscope, its cellular structure becomes visible.



The photomicrograph on the left below shows that the white areas of the petal are composed of cells with no red pigment, while that on the right shows an area where the colour is deep red due to cells containing varying amounts of red pigment.



Tatarian honeysuckle’s reproductive system consists of five bright yellow anthers (male pollen producing organs) supported by white filaments, and a central, bulbous, green stigma (female pollen accepting organ) supported by a white style.



Under the microscope, an anther’s coating of spherical pollen grains is visible.



Higher magnifications reveal the roughly spiked surface of each grain.



Some pollen grains adhere to a filament’s surface.



Close examination of the flower’s green stigma reveals that it is divided into three ellipsoidal lobes.  The photomicrograph on the right shows the rough surface structure of one of the lobes.



Higher magnifications show that a lobe’s surface is covered with short, rounded protuberances that aid in the collection and retention of pollen grains transferred to the flower by insects acquiring the nectar stored at its base.



Unlike the filament, the style supporting the stigma is covered with long hairs.  The image on the right shows a couple of pollen grains stuck to one of the hairs.



When a flower has been pollinated (by having pollen deposited on its stigma), a pollen grain germinates and sends a root-like tube down though the style to the flower’s ovary.  The grain’s male sex germ travels down the tube to an ovule in the ovary where the female sex germ is located.  Fertilization occurs when the two sex germs combine.  After fertilization, the flower’s fruit, (or in this case two fruit) begin to develop.  The image below shows two such fruit with the brown remnants of the flowers’ pistils still visible.



Notice the veined surface of the leaf seen in the image above.  In the lower magnification image at left below, the intricate vein structure at the edge of a leaf can be seen.  The image on the right shows a higher magnification view of one of the principal veins on the underside of the same leaf.  Note the many long hairs that grow out from this central vein.



Still higher magnifications show the hairs more clearly.



By mid July, the many fruit pairs provide the honeysuckle bush branches with a touch of brilliant colour.  Note at the top of the two images, that a fruit transforms from green, through yellow and orange, to its final red colouration.



The abundant fruit of a tatarian honeysuckle bush are visually striking, and much prized by birds as food.





Earlier in the article I mentioned that Tatarian honeysuckle can produce flowers of other colours.  Some distance from the stream, there are several white bushes.



These flowers are identical to the earlier ones, in all but colouration.



Pink honeysuckle flowers are the most common.  Two typical examples of bushes can be seen below.



Once again, only the flower colour is different.



Notice the similarity of the reproductive structures to those seen earlier.



Tatarian honeysuckle readily invades old fields, open woodlands, and other disturbed sites.  It sometimes forms a dense thicket that can restrict native plant growth.  For this reason some jurisdictions  consider it to be an undesirable plant.  Where I live however, this is certainly not the case.  Its colourful flowers and fruit are a welcome sight to any passerby.


Photographic Equipment

Most of the photographs in the article were taken with an eight megapixel Canon 20D DSLR and Canon EF 100 mm f 2.8 Macro lens.  An eight megapixel Sony CyberShot DSC-F 828 equipped with achromatic close-up lenses (Canon 250D, Nikon 6T, and Sony VCL-M3358 used singly, or in combination), was used to take a few of the images.

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)

Little, Elbert L. National Audubon Society Field Guide to North American Trees - Eastern Region. 2004.  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.



 All comments to the author Brian Johnston are welcomed.


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