Close-up View of Two
(Freesia hybrida Hort.)
by Brian Johnston (Canada)
This attractive small flower is native
to South Africa and Australia where it often grows in such numbers in
woodlands and disturbed areas that it is to referred to as an
“infestation”. In Southern Ontario, where I live, the plant is
sometimes available as a cut-flower for use in floral
arrangements. For the purposes of this article, I obtained two
hybrid varieties that had been grown in the Netherlands and transported
by air to Toronto for a nearby exotic flower retailer. This is a
perfect example of how small the world has become, and how fortunate we
are to have such floral abundance at our fingertips!
Freesia grows from a corm, a solid bulb like that of the
gladiola plant. The genus name Freesia
was named after the German physician F.T.H. Freese who died in
1876. The stem usually branches only once and therefore has a
characteristic Y shape.
The two images that follow show
that the buds and flowers grow in a helicoid
cyme, an arrangement in which they are attached to the stem in a
spiral fashion, but nevertheless always face in a single direction.
A higher magnification reveals
several details. The final flower colour is shown only by the tip
of the bud, the remainder being yellow-green. The bud grows up
through dark green spathes
which are conspicuous bracts
(modified leafs) that partially surround it.
Once a flower blooms, a long white
pistil that branches at the tip is visible at its center. The
right-hand image shows a better view of the two spathes that enclose
each bud’s base.
Like many other plants, the buds of
freesia are extremely photogenic. For the purpose of the next
section, take particular note of the top of the spathe in the image at
right. Note that it is not green, but light brown in colour.
If the brown, topmost edge of the
spathe is observed under the microscope, and illuminated by a
dark-ground condenser, it has a rope-like appearance.
Just beneath the edge, in an area
that looks almost white and translucent, individual cells are resolved.
Closer to the opaque green section
of the spathe, the cells are indeed green, and brown veins are visible.
A lower magnification shows these
Look closely at the bottom of the
vein just to the right of center in the image that follows. The
vein appears to be composed of long cells that have a multitude of
closely spaced rings along their length.
After a flower has finished
blooming, it shrivels up and drops off. The enclosing spathe
however, remains attached to the stem and partially dries out appearing
like a papery brown membrane. When this membrane is examined, all
kinds of strangely shaped sections can be seen. The triangular
one below is particularly noteworthy.
The three photomicrographs that
follow show the cells that make up the base of the spathe. (The
brown coloration is due to its age.)
Once a funnel-shaped flower blooms
it is evident that there are two layers of petals. Each layer is
composed of three petals. Typical flowers are 3 to 4 centimetres
The two images below show that some
of the petals curve inwards towards the center of the flower.
When a petal is examined under the
microscope, the red striations that were observed in earlier images can
be seen in greater detail. The cells making up the petal’s
surface are roughly spherical in shape.
A still higher magnification
reveals that the cells have wrinkled rather than smooth surfaces.
As you have seen, the first freesia
hybrid to be photographed has an orange-red colour. The second
hybrid is bright yellow. The bud arrangement is the same as
before, a helicoid cyme. Many of the buds and flowers have their
spathes discoloured by brown spots.
As the buds grow larger, the
spathes are forced to open more, much like jaws.
Notice the strange shape of very
early buds in the lower half of the two images that follow.
Occasionally the bottom of the
flower’s funnel is wrinkled or dimpled as is the one on the left of the
Most blooms are remarkably perfect
The three photographs that follow
show different views of the same section of the cyme.
Since this second hybrid has more
rings of closely packed petals, it is more difficult to see the
pistil. I therefore have removed all of the petals from the
flower in order to obtain the view seen on the right.
A closer view, without the
distractions of the rest of the plant, shows the main features of the
female reproductive parts of the flower. There are three reproductive
‘parts’ called carpels that
are fused together (connate),
part way down the structure. Each of the three stigma tips (the pollen accepting
organ) has a distinctive heart shape that is split open at the base.
Since these stigmas look vaguely like petals they are referred to as “petaloid”.
A photomicrograph of the stalk
supporting the stigmas shows that it has many columnar sections.
The stigma possesses many fine
‘hairs’ or projections that help catch and hold pollen grains.
These projections are connected to
the fan-shaped stigmas.
Higher magnification reveals that
the projections come in different shapes and sizes.
One of the stigmas has this single
spiked projection growing from its base.
Freesias are said to be synoecious, since they have both
male and female flowers in the same helicoid cyme. My two hybrids
seem to be ‘freaks of nature’ since I could not find a single male
flower! In fact, I was unable after much searching, to find any
pollen grains on the petals or stigmas of the plant. (If any
reader can explain this mystery, I would appreciate hearing from you.)
The showy flowers of the Iridaceae family to which freesia
belongs, are widely cultivated. (The crocus, gladiola and iris
are also members of the same family.) By the mid 18th
century, freesia was cultivated in Europe, but it wasn’t until the late
19th century that selective hybridization was
attempted. Today, freesia is grown in very large numbers for the
worldwide florist trade.
The photographs in the article were
taken with an eight megapixel Canon 20D DSLR and Canon EF 100 mm f 2.8
Macro lens. A Canon 250D achromatic close-up lens was attached to the
EF 100mm lens in order to obtain a higher magnification for a few
images. The 250D screws into the 58 mm filter thread of the camera
lens. The photomicrographs were taken with a Leitz SM-Pol microscope
(using a dark-ground condenser), and a Nikon 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
January 2009 edition of Micscape.
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