Close-up View of the Torch Lily
by Brian Johnston (Canada)
The shape and colour of Kniphofia uvaria’s extraordinary
bloom were the inspiration for all three of its common names, Red Hot
Poker, Torch Lily, and Tritoma. Originally found in Madagascar
and tropical South Africa, the plant was brought to England in the
early eighteenth century, and over the years many cultivars have been
produced. One of these, ‘Alcazar’, is the subject of this article.
(named in honour of Johannes Hieronymus Kniphof (1704-1763) , a
professor of medicine at Erfurt University in Germany), is a genus of
plants in the Asphodelaceae
family. Interestingly, the genus Kniphofia is closely related to the
genus Aloe of hand-lotion
fame. Translated from the Arabic, the cultivar name ‘Alcazar’
means Spanish fortress or palace.
The first image in the article
shows the structure of a Torch Lily inflorescence. Keep in mind
that this colourful flower-head is held aloft by a one metre long
sturdy green stem! Most of the bloom is at the bud-stage.
Only a few flowers have bloomed at the very base of the cone-shaped
structure. Botanists refer to such a flower-head as a “dense
indeterminant spikiform raceme”! This particular cultivar
displays shades of yellow and orange, which some describe as “hot
coloured” or the colour of “burning embers”.
To show the blooming process, here
are two images of the flower-head taken four days apart. As you
can see, its flowers bloom from bottom to top. The flower-head
appears at its “best” near the beginning of the process. At later
stages, the many wilting, dead flowers detract from its striking and
unusual structure. (The leaves seen in the background of the
image on the right belong to a second plant that has been raised
vertically. The leaves of the plant don’t grow as high as the
In the image that follows, each
elongated bud (~ 2.5 cm) in the lowermost ring has opened to
reveal the flower’s six short (~3 mm), rounded petal lobes.
Extending down from the open end of the flower are 6 stamens, and a
The two images below show the
flowers’ oval, yellow anthers, and their supporting white
filaments. At this early stage, no pollen is present on the
In this species, the
pre-blooming stage is quite simply, spectacular! The many
tubular, almost banana-like buds are slightly grooved, and have
attractive grayish highlights.
Closer views reveal the subtle
shading displayed by the drooping structures.
In the first photograph below, the
stamens that project from the newly opened flowers are immature, and
yellow in colour. In the last two images, flowers that opened
earlier (lower in the flower-head) possess anthers that are beige or
brown in colour. These have begun to shed pollen.
Let’s look first at the immature
anthers (male pollen producing organs). Each 6-petaled flower
possesses 6 anthers positioned at the ends of supporting white
Higher magnification reveals that
each anther has longitudinal grooves on its “upper” surface. Of
course, since the flower’s open end faces down, the anther’s
“upper” surface faces in the same direction.
Even higher magnification
macro-photographs show that the anther is divided into lobes.
Individual cells can be resolved in the image on the right.
Eventually, each anther begins to
shed pollen, a process referred to as dehiscing.
At this point, the anthers are no longer yellow, but have turned a
reddish-brown. (The image on the right shows “younger” anthers
that have just begun the process.) In both images the long,
white, rod-like structures that extend beyond the stamens are pistils.
At the limit of the magnification
possible with my macro-photographic equipment, individual pollen grains
are visible on an anther’s surface.
By using a microscope, we can get a
still clearer view of the back of an anther, with its point of
attachment to the filament.
A photomicrograph follows that
makes use of dark-ground illumination to show several Torch Lily pollen
grains. They appear ellipsoidal, with pointed ends.
To show only the previous image
would not give a true picture of the shape of these pollen grains
however. In fact, they are remarkably dissimilar in shape from
one sample to the next. Take for example the six grains in the
following photomicrograph. One is almost spherical, two are
ellipsoidal, one is ellipsoidal with a “dimple”, and two are strangely
triangular in shape, also “dimpled”.
At a much higher magnification,
surface detail can be resolved.
A single pistil, composed of a
stigma (pollen accepting organ) and its supporting filament, extends
farther out of the open flowers than do the stamens. Since the
flowers face down, the abundant viscous nectar flows to the tip of the
stigma and drips from it. The droplet in the image hides the
stigma itself, which can be seen at a higher magnification in the image
on the right. Notice the stocky, hair-like projections that cover
the stigma’s surface. These help to retain pollen grains.
In the image below, the flower-head
has reached the age where its lowermost flowers have begun to die, and
disintegrate. Instead of falling off however, they remain in
position – glued in place by the thick coating of sticky nectar that
has dripped or flowed from higher blooming flowers under the influence
On the left below is an image
showing the cellular structure of the fused, or tubular portion of a
flower’s petals. Several pollen grains can be seen adhering to
the surface. On the right is a photomicrograph showing the
stomata and associated guard cells that control gas flow into and out
of a leaf’s underside.
A much higher magnification was
used to produce the two images that follow, showing the surface of a
fused flower tube, and bubbles that have formed in the coating of
nectar on its surface.
Finally, here are two views showing
why a Torch-Lily’s flower-head becomes less visually appealing with
age. As time passes, more and more decaying flower material
accumulates, detracting from the inflorescence’s natural beauty.
Most gardeners remove dead flowers from the flower-head to prevent this
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 Macro lens.
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
The photomicrographs were taken
using a Leitz SM-Pol microscope (using dark ground and phase contrast
condensers), and the 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 August
2009 edition of Micscape.
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