Cyclamen Corolla: After Pollination

Fig. 1   Cyclamen flowers:  before and after pollination.

The cyclamen flower continues to amaze me.  In some of my previous blog posts, I described my observations on the movement of the petals (corolla) prior to fertilization and the eventual behavior of the seed head.  But the uniqueness of the plant has not ended there.  This beautiful plant is more mysterious than I originally thought. 

Fig. 2      Unfertilized flowers fade away.

 

Corolla of unfertilized flowers remains attached to the peduncle. 
It has been my recent observation that the corolla (petal) can fade away in two different manners depending on whether the flower is pollinated or not.  Firstly, flowers that have not been pollinated tend to senesce naturally while they remain attached to the peduncle.  The unpollinated flowers undergo a gradual decline of turgor resulting in wilting of the flowers (Fig.1).  This is then followed by a gradual discoloration of the corolla.  It is noteworthy that the corolla remains with the peduncle when pollination fails (Fig. 1).  The flower failed.

Fig. 3    After pollination flowers turn into seedheads. 

Pollination results in corolla abscission
Secondly, flowers that have been pollinated shed off their corolla shortly after fertilization has taken place (Fig. 2).  In other words pollination results in corolla abscission.  (Abscission is simply the natural separation of any plant part from the main plant system)  It has been established through research that there is a significant increase in ethylene levels on pollinated flowers as compared to the unpollinated ones.  Combine this thought with the common knowledge that ethylene causes abscission among others and we get an explanation for the abcission of the corolla in fertilized flowers.  The flower whose goal was to attract pollinator now enters a new stage - to support the developing embryo.  At this point, the corolla or petal has accomplished its purpose and is no longer necessary - it falls off the flower cleanly.

My "almost-scientific" personal opinion
When flowers begin to lose the flow of fluids and sugars from the main plant (Fig. 1) then how can one expect further production of plant hormones, such as ethylene, from these parts anymore?  So the idea that ethylene is the cause of corolla abscission is kind of counter-intuitive.  There are evidences that show the role of ethylene in the development of the embryo.  The separation of the corolla could be an incidental occurence as the sepals begin to push downward to enclose the recently fertilized ovary (Fig. 4).  In contrast, the unfertilized flower that has already lost its turgor (Fig. 2) no longer have the force to do anything - such as push the corolla off the flowers. 

Fig. 4   The sepal enclosing the fertilized ovary after pollination.

Every plant has a set of unique behaviors which the gardener, given enough time, eventually comes to notice and appreciate.

Breaking Free

Fig. 1   Cymbidium flower bud (March 25, 2010).

The opening of the cymbidium flower is a slow process especially during this season when the night time temperatures are still close to freezing.  The good thing about his is that the flowers can be enjoyed at different stages.  

Petals are beginning to break the tight enclosure of the three sepals (Fig. 1).  The sepals make up the outer whorl of an orchid flower. 

Fig. 2  The sepals beginning to reveal the petals. 

Inside the tight protection of the sepals are the petals.   Cymbidiums have three petals.  Two of them are identical and similar to the sepals in structure.  The third of the three petals is different is shape, texture, and coloration.  It is called the lip or labellum.  I've always wondered why it called so but actually it looks like a lip that has been smeared with lipstick.   This characteristic of the labellum is not obvious in these pictures but it can be observed  from my previous posts.  The yellow tissue that is seen through the small opening (Fig. 2) is called the tongue.  

Fig. 3    Unharmed by the storm we just had.

The opening of the flowers is a concert of events leading towards one goal - pollination.   Each event happens only at the appointed time.  The opening of the petals has to coincide with the production of the right chemicals that produce the smell and the color that attract the right pollinators.   When conditions force the flower to move forward out of schedule, it will fail to accomplish its task. 



Slowly but surely, the flowers are working to do their jobs. 

Lilium

Oriental Hybrid Lilium: The flowers gracefully unfurl...

The other day, my husband brought me a bunch of beautiful lilies (Oriental Hybrids) from Costco.   I could not stop telling him how much I liked them.  From a distance the flowers are pleasing to look at with the delicate shape of the six organized petals that gracefully open into a dramatic spectacle.  On closer scrutiny the flowers are not only elegant but amazing - a perfect explanation of a great design!

I have never owned an Oriental Hybrid plant or any of the Lilium species before so I have not had the chance to observe the plant personally.  Based on my research, I gathered that the Oriental Hybrid group is only one of the nine classifications of cultivated Liliums.  Genetically, these are hybrids derived from the following species:  L. auratum and L. speciosum[1] , and L nobilissimum, L. rubellum, L alexandrae, and L japonicum [2] along with several Japan native species.  The flowers are characteristically large and fragrant.  It contrasts with the rest of the traditional species with flowers that faces downward, these hybrids have flowers that are outward-facing as if looking up to the sky.  Lilium 'Stargazer', a common example of the Oriental Hybrid, got its name from this sky-pointing characteristic of its flowers.

'Stargazer' apparently originated in Humboldt County California through the genius of Leslie Woodruff, an independent plant breeder.  What is interesting is that for such a phenomenal flower, the exact parentage of this hybrid is not known because Woodruff did not document his breeding work in detail.  Obviously he was more concerned about the outcome than the process.  Fortunately this plant can be cloned easily - thus its characteristics are maintained and preserved.

The flowers looks angular when they are unopened.

Pin cushion-like stigma

Apparently there were two varieties (identities unknown to me) included in the bouquet I got... A pleasant provision!  The darker pink flowers boast broad stamens that are covered in golden pollen grains.  The filament that supports the stamen is light green in color.  At the center of the flower is the prominent pistil with a cushion-like stigma that resembles the appearance of a small head of cauliflower. 

Pollens seem loosely attached to the stamens.

The three-lobed stigma looks like a mini-cauliflower head

The other flowers are lighter in color.

The other variety is lighter in color with darker speckles that seem like "outgrowths" on the petals.  The filaments are greenish white in the center of the flower that gradually darkens towards the stamens.  The stamens are covered in chocolate-colored pollens.   The stigma is the same as in the other variety except that the color is purplish

Chocolate powder-like pollens cover the stamens.

Pistil: Purple pigmentation and sticky substance on the surface of the stigma. 

The filaments are white in the center and gradually darkening towards the stamen.

These stamens are beautiful...but today I had to ask one of my daughters to emasculate the flowers.  (Emasculation is the removal of the male reproductive parts of the flower, a procedure that is common in plant breeding.) The pollens contain natural dyes that can stain fabric - so this emasculation was done to protect the table cloth underneath the flower vase.  This is a recommended process for flowers that are used indoors - but since the sharp color of the pollens add so much to the beauty of the flowers; one can delay this process until the pollens begin to show signs of separation from the stamen.

 “And why do you worry about clothes? See how the flowers of the field grow. They do not labor or spin.  ~ Matthew 6:28