A Close-up View of Two Members of the
Hyacinthaceae Family -
“Common Hyacinth” &
Hyacinthus orientalis & Muscari armeniacum
by Brian Johnston (Canada)
I am in love with him
To whom a
hyacinth is dearer
Than I shall
ever be dear.
Edna St. Vincent Millay
Shortly before Valentine’s Day,
stores and garden centres in my area are flooded with spring
blooms. Crocus, hyacinth, narcissus and tulip plants seem to be
everywhere. Perhaps this is a good thing, since the climate of
southern Ontario, where I live, will not support such living things,
out of doors, for at least another three months. The sight of
these attractive flowers, gives a welcome preview of the coming spring!
Most of the hyacinths available
today have been cultivated over many years to improve the size, colour,
and shape of the flowers. Originally based upon Hyacinthus orientalis, native to
the Mediterranean region, the many cultivars available today are
remarkable in their diverse colourations. Even as far back as the
1700’s, two thousand different hyacinths were said to be in cultivation
in Holland (the major commercial supplier).
I suspect that most of us have had
a powerfully scented hyacinth plant at one time or other in our
homes. Do we really look closely at the buds, and flower-heads I
wonder? I think not! The goal of this article is to provide
a detailed look at the structure of three different hyacinth plants,
not so much from the standpoint of biology, but to highlight the
sculptural beauty of their forms.
Here is a pot containing three
bulbs. Notice the very pale green groups of buds emerging from
the leaves that surround them. This light colouration is an
indication that the flowers will be white. Some groups of buds
are stubby and broad, while others are long and thin.
At a slightly earlier stage, one of
the stubby bud groups is still enclosed by the overlapping leaves.
The occasional stem is much greater
in diameter than the others. Note that buds near the tip are
tightly packed, while those lower on the stem tend to be solitary.
The two images that follow show one
of the long, thin bud groups. Notice the small leaflet that
sometimes grows up from the base of a bud.
There is an attractive sculptural
quality which is evident when examining individual hyacinth buds.
At this stage it is difficult to imagine that the green ‘sections’ will
eventually transform into the totally white petals of the mature flower.
Each bud has a single curved green
‘leaflet’ growing out from beneath the bud’s stalk. Strangely,
the size of this leaflet doesn’t seem to be related to the
maturity of the bud.
Proof of this can be seen in the
image below. Notice the very small size of the leaflets beneath
the open flowers.
In the hyacinth flower-head,
flowers bloom from bottom to top.
The same flower-head, a day later,
has more flowers open.
Although hyacinth plants have
straight stems to begin with, as the flower-heads begin to bloom, the
combined mass of stem and flowers is great enough to cause the bloom to
start a slow but inevitable descent to the table top.
If you look closely at this early
stage, the flower resembles a starfish, and the tips of its six petals
are still green.
The petals’ green tips can be seen
in the closer images that follow. The image on the right also
shows the boat-shaped nature of each petal’s tip (top right corner).
Hyacinth leaves are thick, and very
fleshy. A more highly magnified view reveals the many parallel
grooves, and the multitude of microscopic spots on the surface.
Eventually, all traces of the
original green tint disappear from the flowers’ petals.
With time, each petal curves back
towards the stem. At the flower’s centre, the bright yellow anthers (male pollen producing
organs) can be seen. The stigma
(pollen accepting organ) is so short, that it is normally hidden by the
anthers. Note the genetic defect in the flower shown in the
right-hand image. There are two ‘extra’ petals, one of normal
size, and one dwarf petal with an unusual curvature.
The extreme close-up of the centre
of a hyacinth flower shows the group of wrinkled yellow anthers.
The stigma is completely obscured by the overhanging stamens.
Under the microscope, the single
pistil, composed of the stigma, and supporting style with the same
diameter, can be seen to have several pollen grains clinging to its
The three images that follow show
one of the anthers with its coating of pollen grains. The first
image also shows the very short filament at the anther’s base.
The third image shows the rather irregular shape of hyacinth pollen
When a petal is pulled away from a
flower, a thin layer of white tissue often bridges the gap. The
irregular cellular structure of this tissue can be seen in the
The filament that supports an
anther is attached to the base of the petal. As the filament is
pulled from the petal’s base, the tissue exudes a clear, very sticky
fluid. The image at right shows a thick filament of this fluid
clinging to the two surfaces.
Although the general structure of
this cultivar is identical to the previous variety, the light purple
petals, and sky-blue base, make the flowers visually different.
The stem in this variety has a
speckled purple colouration that results in a darker appearance.
The white hyacinth has buds with a
completely green surface, while purple hyacinth buds have a mottled
A close-up of a single bud shows
the mottled colouration more clearly. Notice that even at this
early stage, the bud has a striking blue base.
While comparing the buds in the two
images that follow, notice how the purple colouration deepens as the
As the petals of a flower begin to
open, some still have the remnants of the earlier greenish colour
A short time later, the petals have
opened wider still, and the flowers have a random, unsymmetrical
The short flower stalks are cupped
at the base by very tiny green ‘leaflets’. This is one feature
that is different than the white variety, which has much larger and
Eventually, the flower’s petals
open enough to reveal the reproductive structures. Notice that
although the anthers are deep purple (almost black), the pollen that
coats them is yellow. If you look carefully at the image on the
right, you may be able to discern the top of the pale yellow stigma at
the centre of the ring of anthers.
The genus name of the grape
hyacinth, Muscari, comes from
the Greek word for musk, and
refers to the powerful scent given off by the flowers. This
particular species has clusters of blue, bell-shaped flowers at the
tips of stems. Other varieties have larger more densely packed
flowers that give the appearance of inverted bunches of grapes.
The plant’s buds are tightly packed
in an arrow-head shaped group at the stem’s tip.
As is the case with most flowering
spikes, the flowers of grape hyacinth bloom from bottom to top.
Notice that the fringe of lobes at the open end of the flower has a
The top surface of each bud has a
symmetrical pattern formed by the six lobes of the yet unopened corolla
(ball-shaped base of the flower).
Notice that the blue colouration of
the flower is deepest in the centre of each of the fused petals that
form the corolla. Also note the dark coloured anthers that can be
seen in the open ends of the flowers.
In order to take photomicrographs
of the reproductive structures of a flower, it is necessary to peel
away the tissue of the corolla. The pale blue colour of the
tissue can be seen in the low magnification image that follows.
Two higher magnification
photomicrographs of the sticky inner surface of the corolla show the
many ellipsoidal pollen grains that adhere to the surface.
The corolla’s inner surface is, as
mentioned earlier, completely coated with a clear viscous liquid,
several droplets of which can be seen below.
Occasionally, when studying the
pollen of a flower, one comes upon rogue pollen grains that don’t
belong. The interestingly shaped grain below must have been
acquired at the nursery or garden-centre.
The two images that follow show
flower-heads at different stages of blooming. Notice that the
flower stalks decrease in length towards the top of the flower-head.
If you look into the end of one of
the flowers, the ring of anthers is visible. In the right-hand
image the tip of the pale yellow stigma can be seen, (out of
focus), just to the right of centre.
Under the microscope the entire
pistil can be seen in the left image. The pale yellow-green
pollen covered stigma is supported by a stocky, green-ribbed
style. The cellular structure of the style can be seen in the
image on the right.
At the right side of the left image
below, this same pistil is visible. To its left, several of an
immature flower’s anthers are also visible. The image on the
right shows the bi-lobed nature of the anther more clearly. (Note
that one lobe has matured to a dark red-brown colour, while the other
is still green.)
A mature anther, and supporting
filament, (from below), can be seen in the image that follows.
I hope that the images in this
article have given you a deeper appreciation of the beauty of the
hyacinth, not only at the normal visual distance, but also when viewed
at macroscopic and microscopic levels.
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 several
The photomicrographs were taken
with a Leitz SM-Pol microscope (using a dark ground condenser), and the
Microscopy UK or their contributors.
Published in the April
2007 edition of Micscape.
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