Close-up View of the Hybrid
by Brian Johnston (Canada)
The family Ranunculaceae contains many genera,
including the buttercups, anemones, and delphiniums.
Surprisingly, the plant studied in this article also belongs to this
family. Helleborus is a
small genus, with plants that are markedly different from those of
other members of the family. Its flowers do not have petals in
the normal sense of the word. Instead its ‘petals’ are really
sepals, (modified leaves), that have the shape of ‘petals’, but appear
to be made of thicker, fleshier, leaf-like tissue. In fact, after
the plant has bloomed, these sepals remain alive and heathy,
essentially as long as the plant lives.
Botanists divide Hellebors into two
distinct groups. Those that have visible, above-ground stems are
referred to as caulescent,
while those without above-ground stems are called acaulescent. As you can see in
the image above, Helleborus Ivory
Prince ‘Walhelivory’ does have stems, and so it is considered to
When flowers like the one below
first bloom, the ring of showy sepals has a pinkish-beige
colouration. This colour slowly fades to a more greenish hue
after fertilization. Unlike normal petals, these sepals undergo a
significant amount of photosynthetic activity, the amount of which
increases after fertilization. The greenish hue is evidence of
this photosynthetic increase.
Front and back views of a flower
can be seen below. Notice the absence of greenish, protective
bracts beneath the whorl of sepals. There are however, several
narrow, spear-shaped leaflets on the stalk beneath the bloom.
The point of connection of flower
to stalk can be seen below. Both the plant’s stems, and flowers’
stalks have a reddish hue. The stalks have a multitude of very
tiny, light coloured protuberances over their surfaces.
The three stages in the
life-cycle of a Hellebore flower are shown in the image that
follows. Clockwise from bottom left, there is: the bud-stage, the
blooming fertilization-ready flower, and the post-fertilization
Two examples of the bud-stage of
the plant can be seen below.
The glossy, dark green leaves of
this species are ovate in shape, and have a sharply serrated edge.
Evidence of the caulescent nature
of this Hellebore can be seen in the image below showing an opening bud.
Looking into the open end of a bud,
you can see the light coloured pistils, surrounded at their bases by
many pale yellow, immature stamens. Around the stamens is a ring
of light green tubes, which as we will see later, are the flower’s
nectaries. (In the image at left, I have focused on the tops of
these nectaries, while in the image on the right, I have focused on the
tips of the stigmas.
Notice in the two images that
follow, the strange modified leaflet structure. I have not seen
this particular phenomenon in any other plant that I have studied.
Here is a mature Hellebore
flower. At the base of the sepals, there is a ring of
yellowish-green, tubular, or funnel-shaped nectaries. Some
botanists refer to these as the actual, (highly modified), petals of
the flower that have fused at their edges to form tubes. The
flower’s insect attracting nectar is held at the base of these
nectaries. Inside the nectary ring are many stamens composed of
anthers, (male pollen producing organs), and their supporting
filaments. At the centre of this group of stamens are the pistils
(female reproductive organs).
When a bud first opens, the anthers
are enclosed by yellowish-green anther-caps.
Hellebore flowers are protogynus,
which means that their stigmas are receptive before the stamens release
pollen. This decreases the probability of the flower fertilizing
itself, and encourages cross-fertilization. (In reality however,
a Hellebore flower at a later stage can
fertilize itself, and is referred to as being self-fertile.) In the images,
the anthers and their filaments surround the swollen bases of the
styles – (the ovaries which produce seeds).
At a slightly later stage, the
anthers have taken on a yellowish-brown tinge, but they still have
their anther-caps in place. The image on the left shows several
of the flower’s nectaries. The third image provides another
viewpoint. (The sepals have been removed from the flower in order
to make it easier to differentiate the structures.)
Eventually, the anther caps darken,
begin to disintegrate, and pollen starts to be released.
Higher magnification shows pollen
grains clinging to anthers, filaments, and ovaries.
Here, the flower’s eight white
stigmas (pollen accepting organs) are visible. Each is supported
by a reddish-brown style.
These styles can be seen in the
side-views shown below.
The next stage in the flower’s
life-cycle is revealed below. Can you see what is missing?
Yes, you’re right – the stamens have all shriveled and have fallen from
The images that follow show
particularly well the shape of the flower’s nectaries.
Here finally, is the last stage in
a flower’s transformation. By this time, the nectaries have
fallen away from the fertilized flower, leaving only the (now greener)
sepals, and the group of pistils. The flowers do not decay and
fall from the plant as they do in many other species. These
flowers will continue to look like this until the winter freeze kills
the entire plant!
Hellebores have been cultivated,
mainly in Europe, for hundreds of years. Although all contain
harmful, poisonous alkaloids, they are sometimes used for ‘medical purposes’ in homeopathy and
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.
An 8 megapixel Canon 20D 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
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 May
2010 edition of Micscape.
Please report any Web problems or
offer general comments to the Micscape
Micscape is the on-line monthly magazine
of the Microscopy UK web
site at Microscopy-UK
Onview.net Ltd, Microscopy-UK, and all contributors 1995 onwards. All
rights reserved. Main site is at www.microscopy-uk.org.uk
with full mirror at www.microscopy-uk.net .