Close-up View of White Viper's Bugloss

Books on wildflowers and weeds usually mention that the flowers of Viper’s Bugloss, also known as Blueweed, Blue Devil, Blue Thistle, Snake Flower and Viper’s Grass, are blue in colour. Occasionally mention is made of rare white flowers for this species. Although I kept a constant lookout during the plant’s growing period, I had never come across one. Over the years I have written two articles about the common blue version, and this summer I finally found four white plants in an area containing hundreds of the normal plants. I pass by this area almost every day, and I am certain that the white plants did not bloom in earlier years. Why they suddenly appeared is a mystery.

White Echium vulgare may be rare, but it certainly is not as strikingly beautiful and photogenic as the blue variety. Nevertheless I consider it a duty to provide this article for purposes of completeness. Identical in structure to the blue variety, the only difference is colouration. This situation reminds me of the albino skin pigmentation in humans. It is not just the skin colour that is different, but also the hair and eye colour. All parts of these albino plants are muted in colour as though someone had decreased the colour saturation in Photoshop.

As can be seen in the first image in the article, the flower is funnel-shaped, with five shallow lobes. Notice in the image below that flowers bloom one at a time on each of the curved (like a scorpions tail – hence ‘scorpioid’) racemes. (A raceme is a group of flowers connected to a stem where each flower is connected to the stem by a stalk.) Also notice that the flower’s stamens and pistil extend out beyond the corolla.

Buds appear on the lower scorpioid racemes first.

Simply looking at the upper portion of the plant’s stem, you might get the impression that the many green, pointed bracts, (modified leaves), are covered with very fine, down-like hairs. Warning – that would be a big mistake! Each of those almost microscopic hairs is a hard, fine, glass-like spine able to penetrate skin with ease. Pulling a Viper’s Bugloss plant from the ground with your hand would be a painful experience that you would never forget.

The first image below shows typical Viper’s Bugloss buds. On the right is an image showing a partially open flower.

The frothy bubbles on one of the scorpioid racemes is created by an insect that, as children, we called a ‘spit-bug’.

When viewed head-on, the raceme has a V shape, with longer pointed green bracts framing two rows of shorter bracts that hide the developing white buds.

Under a bud which is about to bloom, there is a particularly long bract that dwarfs the others.

Projecting from the open mouth of the flower are several of its bi-lobed anthers. As yet these structures are not releasing pollen.

Under the microscope, the cells constituting the petal’s surface are clearly visible.

In mature flowers the stamens, and the single pistil project some distance from the front edge of the corolla.

Under the microscope, one of the anthers has started to release its pollen, a process referred to as dehiscing.

Pollen grains appear to have an ellipsoidal shape.

If the surface of a dehiscing anther is examined with higher magnification, sticky, thread-like structures called viscin threads are visible. Usually, these threads link the pollen grains together as they are expelled from an anther.

If you look closely, it is possible to distinguish the lower flower’s pistil in the image below. It is colourless, and the stigma at its tip is forked (bi-lobed). On the right is a photomicrograph showing the entire stigma.

Higher magnification views of one of the two lobes, show that its tip is covered with receptive, rounded bumps.

The plant photographed for this article remained on a table for three days. Two insects seemed to have made the upper stem of the plant their permanent home, since every time I investigated they were happily doing whatever insects do – eating I suppose.

For anyone who has touched a Viper’s Bugloss plant, the most important structures are its pain inducing spines. Essentially every surface except the petals are covered by these glass-like needles.

Higher magnifications show their structure and speckled surfaces.

Finally, here are a few additional images of my insect ‘friends’. They seem unaffected by the forest of lethal spines that constantly surround them.

Back in the mists of time Viper’s Bugloss was thought to be able to expel poisons and venom from the human body, and to cure viper bites. It is because of this dubious ability that it was given the common name Viper’s Bugloss. One early writer stated that “Viper’s Bugloss hath its stalks all to be speckled like a snake or viper, and is a most singular remedy against poyson and the sting of scorpions.” How fortunate we are that we live in an era where the scientific method informs doctors, rather the appearance of the remedy!

Photographic Equipment

The low magnification, (to 1:1), macro-photographs were taken using a 13 megapixel Canon 5D full frame DSLR, using a Canon EF 180 mm 1:3.5 L Macro lens.

A 10 megapixel Canon 40D DSLR, equipped with a specialized high magnification (1x to 5x) Canon macro lens, the MP-E 65 mm 1:2.8, was used to take the remainder of the images.

The photomicrographs were taken using a Leitz SM-Pol microscope (using a dark ground condenser), 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.

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© Microscopy UK or their contributors.

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