by Brian Johnston (Canada)
Persian violet, also called German
violet in North America, is native to the island of Socotra, an
archipelago in the Indian Ocean. In Europe, where it is
cultivated as a house plant, it is referred to as Arabian
Socotran violet, in addition to the names mentioned above.
It is easy to see why the
so popular. Its blue-violet flowers, with prominent yellow
stamens, are contrasted against the shiny green leaves.
pistil of each flower has a distinctive bend which causes it to
almost parallel to the petals. As flowers die, they are
constantly replaced by new ones, causing the overall impression
freshness and constancy.
Persian violet buds seem to me
be particularly photogenic, and strangely, have the shape of
rocket ships. At an early stage, they are bright green,
the leaves, and have five prominent fins.
A little later, the bulbous
of the bud appears white or pale yellow.
After several days, the
packed petals forming the ‘nose’ take on a pale violet colour.
In the occasional bud, the
of petals is particularly three-dimensional.
Most buds however have
Finally, the petals begin to
unfurl, revealing five large, bright yellow anthers.
affine’s mature flowers are 5-merous which means that
possess five petals, five fin-like bracts, and five
petals are rounded, and a lime green colour at their
sturdy lower stalks have very variable lengths, and are
Closer views of a flower
unusual position of its pistil. Instead of growing up
group of stamens, as in a normal flower, it grows parallel to
petals until it is some distance from them. Only then does
bend to be perpendicular to the plane of the flower. This
adaptation may discourage self-pollination.
Still closer views of the
of stamens reveal their triangular shape. It’s not
whether filaments are absent, or whether the base of each
the filament, and the grooved top section is the anther.
Each anther has two
and is referred to as 2-locular. Careful examination of
images below reveal the circular opening at the tip (or apex) of
chamber. It is through these openings that the pollen
the anther is released. The process of pollen release is
dehiscing, and in this species dehiscing occurs through what are
referred to as apical pores. (apical = apex)
A closer view of the two
pores of an anther can be seen in the photomicrograph that
The flower’s single pistil is
composed of a white, sturdy style which supports a pale
stigma. At the magnification shown in the two images that
the hair-like structures that cover its surface are barely
Under the microscope however
structures are easy to see. Their function is to increase
surface area of the stigma, and thus increase the chance of
capture and retention. Note that the tip of each ‘hair’ is
spherical; this normally implies a glandular function.
The flower’s ovary is
‘behind’ the petals, and the five fin-like bracts (modified
mentioned earlier grow from its surface. Notice in the
image the tiny, pointed, green leaflets that point towards the
intersection lines of the petals.
If one of the flower’s petals
examined under the microscope, its cellular structure becomes
visible. Note that in order to increase contrast in the
photomicrographs, Photoshop’s ‘Levels’ function was
This causes the image to display false colours.
Near the base of a petal, each
seems to contain a structure that is bright red. The
function was not used here and so the two images are true
While photographing flowers
Micscape articles, I always appreciate plants with sturdy stems
stalks. These prevent the droopy, vibrating structure
that is the bane of my life. In order to obtain the
that I want, most exposures are in the 1 to 5 second
motion of the plant results in out-of-focus or blurry images
useless. How I wish that all plants had stems and stalks
from rigid green concrete!!!!! I will finish this rant by
complementing the Persian violet for its ability to ‘stand
I photograph it.
A branch-point on one of the
appears to be a marvel of engineering. Some stalks connect
leaves, while others hold flowers.
Leaves in this plant are
opposite one another. Each is glossy green with one
central vein, and two subsidiary veins.
Two photomicrographs showing
underside of a leaf can be seen below. Each of the oval
structures is a stoma and its surrounding guard cells.
control the entry and exit of gases into and out of the interior
A higher magnification
photomicrograph follows showing the leaf’s structure near an
If one searches for
my area, garden centres have very few Persian violets, and very
African violets. This is a shame, because the plant
in this article is easy to grow and beautiful to look at.
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
December 2013 edition of Micscape.
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