Close-up View of the
Pulsatilla vulgaris 'Rubra'
by Brian Johnston (Canada)
The pasque-flower belongs to the
Buttercup family (Ranunculaceae),
and is closely related to the genus Anemone.
For this reason, one of the alternative names for the plant is “meadow
anemone”. It is native to the short turf, and alpine
meadows of North America, Europe, and Asia. The Pulsatilla vulgaris species is
native to Great Britain, but it is now very scarce in the wild.
Pasque-flowers’ finely dissected leaves, colourful blooms, and silky
coating of fine hairs, make it a popular garden plant.
The genus name Pulsatilla is
derived from the Latin pulso
which means to strike, or set in violent motion. Why
this name was chosen is not entirely certain, although it may refer to
the fact that all parts of the plant are poisonous and may cause
stomach distress if ingested. Vulgaris,
the species name, translates to common.
The common name pasque-flower was given to the plant, due to the fact
that it flowers around Easter time. In Hebrew, the term for
passover is pasakh, hence
This article focusses on the red variety of Pulsatilla called
‘Rubra’. Other available colours are purple-violet, and
white. Cultivars have been produced with mixed colours, and even
The image above shows the main characteristics of a pasque-flower
bloom. It has six velvety petals with curled, pointed tips,
surrounding a ring of bright yellow stamens, and a mass of pink-tipped
pistils. All plant surfaces are covered in fine, soft hairs as
can be seen in the images below. Note in the right-hand image,
the location of the bracts (modified leaves). In many flowers,
these are positioned right beneath the bloom, but here they are
considerably lower - midway between bloom and leaves.
A partially opened flower can be seen in the images below. The
most striking characteristic (other than the intensity of the bloom’s
red colour), is the length and density of the downy hairs on the
surfaces of the plant.
The top surfaces of petals feel velvety to the touch, but there are no
significant hairs present.
Two photomicrographs show a petal’s upper surface at low (left), and
high (right) magnification. The hairs seen in the left image are
extending into the view from beneath the petal. The image at
right shows the roughly spherical shape of the petal’s cells.
(The colour difference in the right image is due to the fact that Photoshop’s ‘auto-levels’ function
was used to increase contrast.)
In contrast to the upper surface, a petal’s lower surface is extremely
Note the darker red spots, and three-dimensional radial veining,
visible on the petal shown below. The photomicrograph at right
shows some of the hairs growing from the petal’s surface.
Three views of a fully open pasque-flower bloom follow.
If a flower’s petals are removed, the mass of reproductive structures
is easier to see. Multiple rings of stamens, consisting of yellow
anthers (male pollen producing organs) supported by paler yellow
filaments, grow from the flower’s base. At the centre of the
group of stamens is a column formed by many styles, topped by light
pink stigmas (female pollen accepting organs).
An immature anther can be seen below. The first image shows the
overall bi-lobed structure. The second reveals the point of
connection of filament to anther, and the last image shows the hairs
that grow from the surface of the filament.
A mature anther has a less smooth, more bumpy surface, with occasional
adhering pollen grains.
Another example follows.
The two images below show the column formed by the many stigmas (pink),
and their supporting styles (yellow-green). The tip of each
stigma stands out, as it seems to be semi-transparent.
One-half of a flower’s stamens were removed to obtain the view shown
below. Notice how the pistils spiral, from stigma tip to style
base. The bottom ends of the styles are hidden in a dense mass of
long white hairs.
Two views of a stigma tip, from different angles, can be seen
below. Notice that the top-most cells are spherical, whereas
lower ones are tubular in shape.
Along their length, the styles are covered in tiny hairs.
Stamens and pistils are joined at their bases to the bulbous structure
shown below. This is the ovary (seed producing organ). The
image at right shows the flower’s hairy stalk.
Although the top surface of a leaf has few hairs, tufts of long white
hairs grow from the tips of each of the leaf’s lobes.
The under-surfaces of leaves have many long hairs, as can be seen in
the photomicrograph below.
Also present are many oval stoma, and associated guard-cells, that
control gas entry into the internal structure of the leaf.
The pasque-flower is not native to the area in which I live, but it is
readily available in garden-centres in springtime, for planting in the
garden. Although its flowers are small, about five centimetres in
diameter, their deep colour, and the plant’s downy surfaces, make it an
attractive addition to the flower-bed.
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 Chemical Crystals
A complete graphical index
of all of my crystal articles can be found here.
Microscopy UK or their contributors.
Published in the July
2008 edition of Micscape.
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