Close-up View of
Cucurbita pepo var. ovifera
by Brian Johnston (Canada)
Each autumn, garden centres sell mesh
bags containing a random assortment of ornamental gourds for use as
home decor during the fall period. As a change from my usual
flower articles, I thought that it might be interesting to investigate
these attractive gourds using my macro-equipment.
The strangely shaped objects studied in this article are the
hard-skinned fruit of members of the Cucurbitaceae
family. Their appearance hints that they are closely related to
the common edible squashes and pumpkins, and this is the case.
The fruit shown in the article are all produced by plants referred to
as Cucurbita pepo
A wide variety of shapes are displayed by fruit of this genus, from
spherical, through pumpkin-shaped, to pear-shaped. The surfaces
may be smooth, ridged or warty, and may have a single colour, or
display a variety of interestingly coloured patterns.
For thousands of years cultures around the world have grown gourds, not
only for food, but as storage containers, utensils, and
ornaments. The one to six month process used to turn the
soft-skinned, fleshy fruit into a hard-skinned gourd hasn’t changed
much over the centuries. First, the fruit are thoroughly washed
with soap and water, and then dried. (Today, isopropyl alcohol
[rubbing alcohol] is applied to the exterior surfaces to kill bacteria,
and reduce the possibility of rotting.) In order to promote the
drying of the outer surface layer, they are placed onto slotted trays
and kept in a dark, dry, well-ventilated location. After a week
or two under these conditions, their skin has hardened, and their final
colour is apparent.
The second step in the process takes much longer. Here, the
internal tissue of the fruit is dried by storage in a dark, warm, well
ventilated location, with occasional turning to promote even
curing. Small gourds, like the ones shown in this article,
take about a month to dry, but much larger ones may require six months
to fully cure. The hardened shell of the cured gourd may be
waxed, or it may be varnished or shellacked in order to preserve the
integrity of the surface. It should be noted that many gourds are
painted, or otherwise decorated to produce ornaments, but the ones
shown in this article have their natural colouration.
Our first decorative gourd is pear-shaped, with both ridges, and
warts. The colouration is a mixture of bright yellow-orange, and
Up close, these features are almost alien in their strangeness!
During the growth of this particular fruit, it must have received a
scratch along one of the ridges on its surface. As part of the
healing process, light brown tissue filled in the gap, and produced a
permanent scab-like structure.
At the base of the gourd, where the fruit’s stalk was attached, a bit
of decay or mold has been preserved by the curing process.
Our second gourd is also pear-shaped and ridged, but its warts are
larger. In addition, its colouration is composed of darker orange
areas, and a mixture of shades of green and black.
The base has a distinctive radial pattern of black bands.
Most of the warts are located on the surface of the spherical base.
Higher magnification reveals the speckled colouration of these warts.
Even the strange, black, flow-like patterns in the region between
orange and black have interesting details.
The next four images form a sequence with ever increasing
magnification, showing a particular location in the dark area of the
gourd. Notice the green and beige flow-like pattern. I
wonder what caused this striking surface texture. Could it be the
result of some damage during the growth of the fruit?
Here are two views of a particular location in the green area.
Why are the edges of the ‘cracks’ coated with beige particulate
Another such area is shown below. Here the green colouration is
slightly different, and there is an orangish tinge in some locations.
The third gourd is also pear-shaped, and is entirely orange in
colour. It too displays ridges and warts.
The Cucurbitaceae family produces an amazing array of colourful and
multi-shaped fruits. Seven hundred or so species produce a range
from the marble-sized “jumbie pumpkins” of the Caribbean islands, to
giant gourds with a length of two metres!
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
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 images.
The Wild & Wonderful World of
A Flower Garden of
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Microscopy UK or their contributors.
Published in the
November 2008 edition of Micscape.
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