Close-up View of the
by Brian Johnston (Canada)
The unusually shaped bloom of this
plant is best described as “bizarre”
or “weird”! A bright red,
flattened fan shape is topped by a series of convoluted ridges to form
a flower-head composed of hundreds of tiny individual flowers.
The bloom is approximately 13 centimetres high, and 12 centimetres wide
at the top. The flattened triangular base is about 2 centimetres
Celosias are members of the
amaranth family (Amaranthaceae).
The particular cut-flower photographed for this article is a cultivar
of wild Celosia argenta
called “cristata”. Wild
celosias are native to the equatorial tropics of Africa, Asia, and
South America. The common name for the plant comes from the
flower-head’s resemblance to a rooster’s comb. Alternative common
names are “feathered amaranth”, “wool-flower”, and “red fox”.
In the closer view below, the small
individual flowers growing in the triangular base are just
visible. The flowers at the bloom’s base are lighter coloured
than those positioned higher up.
The plant’s fleshy stem has a large
diameter, and is strongly ridged. Notice the tiny membranous
“leaflets” (for want of a better word), that grow randomly from the
As can be seen below, the tiny
flowers are very tightly packed on the flat surface of the
flower-head. They bloom in order from bottom to top. The
many cream coloured specks are actually the flowers’ anthers.
Just below the fringe at the top of
the bloom there are many unopened, tightly packed, torpedo-shaped buds.
A closer view of the convoluted
fringe shows it to be composed of many overlapping bract-like
structures with cream coloured bases, and bright crimson pointed tips.
A bright yellow band separates the
two sides of the bloom’s fringe.
When viewed from above, the folded
shape of the fringe becomes evident. The many bright red “hairs”
growing out from the yellow tissue are less than a millimetre in length!
The close spacing of the plant’s
flowers can be seen below.
Flowers are spaced farther apart on
the narrow “edge” of the triangular section of the flower-head.
The flowers shown below are
completely open. If you look very carefully at the image on the
right, you may be able to distinguish stamens, and the occasional
pistil in the flowers’ open ends.
Several additional views of flowers
at higher magnification can be seen below.
In the very high magnification view
of a single flower that follows, notice that the bases of the pink
petals are green in colour. Also note the tiny “bractlets” at the
top of the flower’s short stalk.
Close study of the flowers below
reveals the oval, cream coloured anthers
(male pollen producing structures) and bright pink, hair-like pistils (female pollen accepting
structures) that constitute the reproductive organs.
Under the microscope, the
arrow-shaped anther can be seen to be liberally coated with pollen
grains. Notice the bright red filament
that supports the anther.
Two examples of pistils from
different flowers are shown below. The stigma has about the same
diameter as the style that supports it. Pollen grains clinging to
the stigma can be seen clearly in the image on the right.
A much higher magnification of the
stigma reveals the tiny spherical protuberances on its upper surface.
At the base of the pistil, there
are a number of roughly spherical “fruit”.
The higher magnification image on the right shows surface detail, and
an “out of place” pollen grain.
The bright green lance-shaped (lanceolate) leaves of the plant are
Views of a leaf’s upper surface
(left), and cellular structure (right) follow. Note the many
pollen grains clinging to the leaf’s surface.
The back surface of a leaf is more
contoured than the front.
The extraordinarily shaped and
coloured flowers of the cockscomb make it ideal for use in large-scale
planting in public places. The unusual blooms certainly provoke
Most of 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
A few photographs were taken with
an eight megapixel Sony CyberShot DSC-F 828 equipped with achromatic
close-up lenses (Canon 250D, Nikon 5T, 6T, Sony VCL-M3358, and shorter
focal length achromat) used singly or in combination. The lenses screw
into the 58 mm filter threads of the camera lens.
The photomicrographs were taken
with a Leitz SM-Pol microscope (using a dark ground condenser), and 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
February 2009 edition of Micscape.
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