A close-up of the wildflower Viper's Bugloss

In a Micscape article written several years ago, I presented images of a dwarf viper’s bugloss plant that I had found late in the growing season. It was a mere ten centimetres high, and certainly didn’t look like the typical plants shown in wildflower references. During the intervening years, I have found many taller and more representative plants in my vicinity. Strangely, the best examples seem to be found in the most unlikely locations. Several shown in this article were growing up through cracks in the concrete median of a four-lane highway. Previous experience has given me great respect for the entire plant’s coating of tiny, but vicious, hair-like spines, and so I arrived on the scene with a pair of pliers, a pair of garden shears, and a cardboard tube. Holding the base of the stem with the pliers, I cut through it with the shears, and then, again using the pliers, pushed the base into the cardboard tube. It was then easy to transport the plant without injury to my hands. A small group of people walking beside the highway had stopped to watch, and they talked animatedly to one another during the process. Traffic noise prevented me from hearing what they said, but I can guess that it had something to do with my sanity!

Viper’s bugloss, sometimes called ‘blueweed’, belongs to the Borage family (Boraginaceae), members of which usually have flowers that are attached to one side of a coiled branch resembling the tail of a scorpion. This coiled branch, or ‘scorpioid cyme’, uncoils as the flowers bloom. The name ‘Viper’ is thought to derive from the shape of the plant’s seed, which resembles a viper's head. ‘Bugloss’ is derived from the Greek word for "ox tongue", since the leaves are thought to resemble this part of the animal’s anatomy.

The plant shown below is approximately 40 cm high, and at the peak of its blooming cycle. Notice that the stems that branch out from the main stem are completely covered in small green sepals, (modified leaflets), that cluster around the base of buds and flowers.

At the tip of another younger plant, the uncoiled scorpioid cymes have many tiny pink buds, and the occasional flower on their upper surfaces. What looks like a fuzzy coating of downy hairs is actually a forest of cruelly sharp spines able to penetrate skin with ease!

Here is a front view of two cymes, each with a single blooming flower and many pink buds. The cyme blooms first near the stem. The tips of the two cymes in the image are coiled back towards the stem beneath the flowers. Notice the red spots on the main stem.

The two images below graphically demonstrate why it is unwise to handle Viper's Bugloss without gloves! In the first of the two, a young stem has very sharp, clear, almost crystalline hairs with reddish, swollen bases. The second image shows an older stem with additional fine, softer hairs covering its surface.

Compare the front view of a cyme seen at the bottom of the left image, with the side view in the image on the right. Notice the bubbles of insect ‘spit’ at the base of the cyme in the right-hand image.

Just to the left of the blue flower in the image that follows is an older bloom that has shriveled up, and turned a deep purple colour.

Notice in the image below, that buds are pink in colour, young flowers are pinkish-purple, and mature flowers are intensely blue.

The photograph that follows shows the main features of the flower. There are five shallow lobes along the edge of the fused corolla. Two of the lobes are larger than the rest, and project out farther than the other three. The outer surface of the corolla is covered in fine hairs (sericeous), but the inner surface is hairless (glabrous). Five stamens, (the male, pollen bearing organs), are usually present along with a bi-lobed stigma, (the female organ where pollen lands). Both the stamens and pistil protrude from the corolla (are exserted). Most flowers are one, to one and a half centimetres in diameter.

At the base of the flower there is a ring of long, thick, bristly sepals (modified leaves). After each flower has finished blooming, it shrivels up and falls away, leaving the ring of sepals which can be seen in the image below.

Each stamen is composed of a hairless red filament which supports a grayish-green anther. One of the stamens is usually considerably shorter than the rest. The flower on the left, in the left hand image, clearly shows the arrangement of the corolla’s lobes.

The number of spiny sepals on each cyme is great. If you look very closely at the image on the left, you can see a tiny drop of blood (mine!) released by a finger when I accidentally touched the plant while preparing to take a photograph. (This plant is even more difficult to work with than those of the thistle family!)

As a viper’s bugloss bud develops, its colour transitions through white, pink, red, and finally in the open flower, to blue.

The anthers of a flower are so small that it is not possible to get a close-up macro-photograph with all of them in focus. Notice in the left image, the hairiness of the corolla’s outer surface. In the right image, notice the curved immature filaments that can be seen in the open ‘mouth’ of a bud.

Using a microscope equipped with dark-ground illumination reveals the detail of one of the anthers. Most of the pollen grains appear to be white, and several fine threads can be seen between grains.

A photomicrograph of the filament reveals that it is not as smooth as it looks to the naked eye. Several pollen grains are visible clinging to its surface in the image.

By adjusting the focus of the dark-ground condenser, it is possible to accentuate different details. The filament holding the anther is out of focus in the lower right of the image.

The image below shows another anther that appears to be completely encrusted with translucent pollen grains.

The hairy pink style supports a bi-lobed stigma.

At the end of each of the stigma lobes there is the bulb-shaped protuberance visible in the dark-ground image below left. The bulb appears to be covered in strangely shaped protuberances that can be seen in the image on the right.

With the aid of phase-contrast illumination, the spots on one of the hairs of the style can be resolved.

The object below was also present on the surface of the style. I am not certain what it could be. (Perhaps a fungal spore?)

Blue wildflowers are not uncommon, however very few have the startlingly blue colouration of viper’s bugloss. Although difficult to handle without blood-loss, it is definitely one of the stars of the botanical kingdom.

Photographic Equipment

Some of the macro-photographs were taken with an eight megapixel Canon 20D DSLR equipped with a Canon EF 100 mm f 2.8 Macro lens which focuses to 1:1. A Canon 250D achromatic close-up lens was used to obtain higher magnifications in several images.

Other photographs were taken with an eight megapixel Sony CyberShot DSC-F 828 equipped with achromatic close-up lenses (Canon 250D, 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.

Still other photographs were taken with an five megapixel Sony CyberShot DSC-F 717 equipped with the achromatic close-up lenses mentioned in the previous paragraph.

The photomicrographs were taken with a Leitz SM-Pol microscope (using dark-ground and phase-contrast condensers), and the Coolpix 4500.

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.

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.

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