Close-up View of the
'Seiryu' Formosan Blue
by Brian Johnston (Canada)
formosana ‘Seiryu’ is renowned for the blue colouration of the
tips of its sepals and petals. (References refer to these as
tepals since “they” say that the flower’s sepals and petals are
indistinguishable. In reality, this is simply not the case, and
so in this article, I will refer to them as separate entities.)
The cultivar name ‘Seiryu’ refers to the Japanese name of one of the
four gods of the Celestial directions.
As is true of most Toad-Lily
plants, this one blooms during the fall, and if the weather permits,
may actually continue blooming until November! Although
considered low-growing and semi-creeping, the example photographed for
this article had some upright stems to about twenty-five centimetres in
Of the three Toad-Lily cultivars
that I have studied, only one, Japanese Toad-Lily (Tricyrtis hirta ‘Miyazaki’ )
produced seed-pods. In both of the other plants, when the flowers
completed booming, they simply shriveled up and dropped off. For
this reason most Toad-Lilies are propagated by root cuttings, stem
cuttings, or by division.
In the bud stage, the flower’s
three sepals protect the interior petals and reproductive organs.
At the base of each sepal is a light-green, bi-lobed spur that acts as
a nectary in the blooming flower. Notice the hairiness of both
the bud’s stalk, and the outer surface of its sepals.
Blue Toad-Lily flowers are small,
(~ 25 mm), but spectacular nevertheless. They are star-shaped,
with an outer whorl of three oval sepals, and an inner whorl of three
narrow petals. Three bright red styles extend out, umbrella-like,
above the petals.
A side view shows the red-spotted
column at the flower’s centre formed by the flowers six
filaments. These filaments curve outwards, and a light-brown
anther hangs from each.
The flowers of Tricyrtis formosana ‘Seiryu’ are
simply spectacular. The range of hues displayed is extraordinary,
from blue through mauve to white, red and beige. Compared with
many other Toad-Lily cultivars, this one seems to display fewer spots,
and thus the viewer concentrates on the overall colour scheme rather
than being distracted by the spottiness.
Notice in the two views shown
below, the dramatic difference in the shape of the wide sepals, and
narrow petals. Even at maturity, these sepals and petals don’t
open out much more than the ones shown in the image.
The three bi-lobed nectaries
mentioned earlier can be seen at the base of the sepals in the image
below. Note that the outer surfaces of petals and sepals have no
The images that follow show the
flower’s reproductive structures. Six light brown anthers that
face down towards the flower’s centre are held aloft by the curving
ends of purple spotted filaments. Above these male organs, are
the brilliantly coloured, forked ends of the three styles. If you
look carefully, you can see the small white patch at the tip of each
fork – the stigma. Like most other Toad-Lilies, this one has tiny
glandular protrusions along the edges of its styles.
Each anther is connected to its
supporting filament by an extremely narrow thread of tissue. A
crevice divides the anther into two lobes. Notice in particular,
that the upper surface of the anther is smooth at this point.
If you examine the two images below
carefully, you can see that a change has taken place. Time has
past, and the upper surfaces of the anthers now look ragged and rather
The side views that follow show
this same phenomenon. If the six, red-spotted filaments were
removed, what would we see?
The answer is shown below. At
the base of the three styles is the light green, three-chambered ovary.
Careful examination of the flower’s
anthers reveals that they are producing pollen grains on their edges,
and on their lower surfaces (not visible from above).
The upper surfaces of some of the
anthers have curled, revealing the pollen covered surface beneath.
The flower’s three glandular-edged,
and stigma-tipped styles are visible below.
Higher magnification reveals more
details. The stigma pad on each style fork generally faces down
towards the flowers sepals and petals. A spherical, membrane
covered liquid droplet is exuded from each tubular stalk to form a
As one moves towards the
reproductive structures, it finally becomes possible to resolve the
graininess of individual pollen grains.
Much higher magnification shows the
tiny, thread-like connection between a filament and the anther that it
During the early stages of growth,
an anther produces pollen, but the grains are contained within the two
semi-circular chambers that can be seen on the right in the image
below. Eventually, each chamber “unzips” along its length to
reveal the pollen within. Botanists say that the anthers dehisce at this point, and release
their pollen. This is the process shown at right in the
image. Eventually both lobes completely “unzip”, and the anther
looks like the one at left.
For comparison, here is a much
closer view of each stage.
How blue a Tricyrtis formosana ‘Seiryu’ sepal
or petal appears depends upon the colour temperature of the
illuminating light, and the angle of view. Daylight seems to
exaggerate the blueness. The image on the right shows a sepal,
and the tuft of short hairs that project from its tip.
Ketzel Levine, (Talking Plants on National Public
Radio), describes Toad-Lily flowers as "surrealistic fantasies which
stand on three rubber boots." Despite their small size, they
certainly produce a stunning visual impact when viewed close-up!
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.
A 10 megapixel Canon 40D 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
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 March
2010 edition of Micscape.
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