by Brian Johnston (Canada)
There are several “speedwells” that grow
wild in Southwestern Ontario. Common speedwell (Veronica officinalis), and
thyme-leaved speedwell (Veronica
serpyllifolia) both have trailing stems that tend to form mats
covering roughly circular areas of lawns and waste areas.
Creeping speedwell possesses these same characteristics, but it is a
hybrid (discovered at the Waterperry
School of Horticulture in England), available at garden centres
for use in rock gardens.
‘Waterperry Blue’ is an evergreen groundcover with deep green leaves
that turn burgundy as the temperature decreases. If it is grown
in an area with mild winters (not
Ontario!), the colourful foliage is maintained through the
winter. In spring, the plant has a mass of lavender blue flowers
with a diameter of about 1.25 centimetres (larger than the wild
varieties). Under good conditions, the plant may re-boom several
times during the summer.
Although the genus Veronica
was for many years considered to be a member of the figwort family (Scrophulariaceae), modern DNA
evidence suggests that it belongs instead in the plantain family (Plantaginaceae). The genus
name Veronica is thought to
derive from the Latin vera
which means true, and eicon which means image. This relates to the
legend of Saint Veronica.
The reason for the plant’s popularity can be seen below. Lavender
blue flowers with white centres, and dark blue veins, liberally cover
the mass of green stems. (In fact the species name peduncularis means stalked,
referring to the lengthy stalk that connects each bloom to the main
At the tips of the many stems, there are groups of unopened buds, each
of which is clasped at its base by a ring of four light green sepals
Notice that as a bud matures, it becomes deeper in colour, and the
sepals at its base begin to open out in readiness for blooming.
The development of a bud, from early to late stage, can be seen in the
image below, as you look down the cluster. Notice the fine white
hairs that coat the surfaces of both stalks and stems.
Distinguishing characteristics of speedwell species can be seen in the
images that follow. Flowers have four rounded petals, one of
which is smaller than the rest. Also, notice the two protruding
stamens, and single protruding pistil possessed by each flower.
A back view of a bloom reveals the four sepals that were seen earlier
surrounding a bud.
Under the microscope, the cellular structure of a creeping speedwell
petal is visible. The colour difference between stripes, spots,
and the lighter background is accentuated in the two images because Photoshop’s “Auto-levels” function
was used to increase contrast.
Up close, the two stamens, consisting of brown pollen covered anthers
(male pollen producing organs), and purple filaments, are visible.
A photomicrograph of one of these anthers can be seen below. A
higher magnification view of the filament’s cellular structure is on
Front, side, and back views follow, that show another anther, and its
Many ellipsoidal pollen grains coat the anther’s surface.
Between the two stamens, you can see the flower’s single pistil,
consisting of a light coloured, bulbous stigma (female pollen accepting
organ), and supporting long, thin style.
Two photomicrographs follow that show the stigma’s receptive surface
(left), and the style (right).
Since this plant was obtained in May, the leaves’ cold-weather burgundy
colouration has almost disappeared. The leaves are deeply veined
Notice in the following image that the leaves are opposite, and
connected to the stem by short stalks. The stem is very hairy,
while the leaf stalks are hairless. There are interesting
protuberances just beneath the uppermost leaves.
The rounded, saw-toothed edge of one of the leaves can be seen in the
photomicrograph at right below.
Higher magnification reveals details of the vein structure.
Numerous stoma, and their associated guard-cells are visible.
These structures control gas entry into the leaf.
Many of the leaves have blemishes similar to those seen in the
following high magnification images. I suspect that a ‘creature’
was living at some earlier period within this spherical chamber.
No signs of actual creatures were to be found, however.
Unlike many other flowers, creeping speedwell does not hold on to its
petals very tightly. The slightest breeze, or vibration will
cause the ring of four petals and attached stamens to fall intact from the bloom, leaving only
the sepals and pistil behind. The green swelling at the pistil’s
base is the ovary (seed producing organ).
Although the flowers of the creeping speedwell are small, their sheer
number and beautiful colour make a striking impression.
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.
The photomicrographs were taken with a Leitz SM-Pol microscope (using a
dark ground condenser), and the Coolpix 4500.
A Flower Garden of
A complete graphical index of all
of my flower articles can be found here.
The Colourful World of
A complete graphical index of all
of my crystal articles can be found here.
Microscopy UK or their contributors.
Published in the April
2010 edition of Micscape.
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