Italian Heath Plant
by Brian Johnston (Canada)
The spectacular flowers, and compact
habit of this shrub make it an ideal houseplant or landscaping
addition. Although the plant is sold at my local garden
‘Italian heather’, it is in fact a member of the Ericaceae family – genus Erica. Heathers are
identified by the genus Calluna.
evergreen shrubs, however heaths have needle-like leaves,
while heathers possess short, scale-like, overlapping
Italian heath’s species name ventricosa
is derived from the Latin ventricosus
which refers to the inflated or swollen shape of its
From a distance, the plant
definitely catches ones attention with its tightly packed
leaves, and multitude of buds and flowers. When viewed
however, its truly remarkable characteristics are
main reason for this is that its flowers are relatively small,
mm in length. The first image in the article shows such a
For comparison, here are two
of the plant from a distance.
Many strong vertical branches
huge numbers of bright green, shiny leaves. Intermingled
these leaves are large numbers of white buds, and flowers with
pink tips. No matter when you look, each branch has both
flowers. As buds bloom, new buds appear almost as if by
Let’s look at the blooming
of the Italian heath. Very early stage buds are pale green
white in colour, and are almost completely obscured by the whorl
long, narrow, green sepals that form the calyx.
These sepals can be seen more
clearly in the two images below. Notice that the sepals’
brownish-red in colour.
As time passes, the buds
in length until they are longer than the sepals. At this
their only colouration is an extremely faint pink band below
Next, the tip of each bud
slightly in size above the band mentioned above, and it takes on
Finally the four petals that
previously formed the bud’s tip open out to form the star shape
top of the flower. The overall appearance the flower is
remarkably similar to that of an urn which tapers to a narrow
and flares to four pointed lobes.
If one of these pointed lobes
examined under the microscope, it is seen to possess a number of
slender, white, hair-like structures growing along its edge.
The photomicrographs below
cellular structure of the body of the lobe (left), and its edge
A view directly into the front
the flower shows hints of the yellow pollen covered anthers
at the level of the narrowing in the tube.
If the urn-shaped flower tube
grasped carefully by the lobes, and pulled gently while holding
base of the sepals, it is possible to completely remove the tube
leaving the reproductive structures untouched. A single
and numerous stamens are visible. Note that the stigma is
positioned at the same height as the midpoint of the anthers.
Before blooming, the flower’s
anthers are busy producing pollen within their interiors.
point they begin to release this pollen, a process called
dehiscing. In the case of Erica
ventricosa, pores open in the sides of the anthers
the pollen escapes.
The image below shows that
anther consists of two lobes.
Photomicrographs follow that
the two mirror image lobes, and their prominent pollen releasing
photomicrographs show a pore, and the edges of anther lobes in
As mentioned before, the
stigma is positioned precisely at the same level as the pollen
releasing pores of anthers. This seems strange since this
promote self-pollination. It is possible that, as in some
species, the flower’s stigma is not receptive to its own pollen.
Both macro and micro views of
flower’s pistil can be seen below. Note that in the
images the supporting style is yellowish-green, while here it is
red. The earlier images are from a newly opened flower
these are from a mature flower. The stigma itself is dark,
black in colour.
The leaves of this plant are
described as ‘typically ericoid’, which means that they are
narrow, and pointed. In addition, they are covered with
colourless hairs, and especially near the tip, have a
groove on their outer surface.
Photomicrographs show this
and the many surface hairs more clearly. The last three
show that the interior of each leaf, near its tip, is actually
and that the interior is completely covered with short hair-like
Here are two views showing
near the base of the plant. Strangely, these leaves do not
the groove mentioned earlier. It seems as though the
leaves occur only beneath flowering tips of branches.
The lack of a groove is
the first of the photomicrographs below. The second and
show views of the hairs that cover the leaf’s surface.
One description of Italian
that I read describes the shrub as being “well-branched”.
certainly true, as can be seen in the following image. The
itself is very tough and difficult to cut.
Italian heath’s flowers have,
we’ve seen, a very attractive shape. What is not evident
photographs is that they possess the ‘look’ of fine porcelain,
the have a shiny wax-like texture when touched. They truly
The low magnification, (to
macro-photographs were taken using a 13 megapixel Canon 5D full
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
lens, the MP-E 65 mm 1:2.8, was used to take the remainder of
The photomicrographs were
using a Leitz SM-Pol microscope (using a dark ground condenser),
the Coolpix 4500.
A Flower Garden of
A complete graphical index of
of my flower articles can be found here.
The Colourful World
A complete graphical index of
of my crystal articles can be found here.
Microscopy UK or their contributors.
Published in the
November 2013 edition of Micscape.
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