I'm Back from the Philippines

Typical rain in the Philippines.

Some of you might have noticed my recent lack of "blogtivity".  The reason is simple - with my family, I traveled to the Philippines.  Originally I planned to take a laptop with me however in a desire to travel lightly; my husband thought that an iPhone was sufficient.   I found out later on that writing on a touch screen is ineffective for gardener's fingers like mine.  Then I though that I could also post pictures knowing that they can speak louder than words...but sometimes life is not all that simple.   Two of the three small cameras we brought stopped working when we got to Cagayan, the northern-most province of the Philippines.  It was raining so hard that moisture must have penetrated the casing of the cameras.   The only one that remained functional was the one that was stored it in a ziploc bag.   

The Philippines has a Tropical Marine climate as influenced by the sea.  It is always hot with always high atmospheric humidity.  There are only two climates namely wet and dry seasons.  Although it is expected to rain every month, some months (June to November) are extremely rainy due to the monsoon winds.   The rest of the months (December - May) are characterized by lower precipitation due to the dry trade winds.  

Did you know?

1.  The English word "boondocks," comes from the Tagalog word "bundok", meaning "mountain.

2.  The Philippines is composed of 7,107 islands.  Some of them cannot be seen during high tide. :)

3.  The Philippines was a colony of Spain for 300+ years (1521-1898). 

4.  The Filipinos were first introduced to the English language by the British invaders in 1762.

5.   Today English language is taught in schools starting from third grade.  It is the official medium of instruction in high school and college.

6.  The Philippines has the same land area as Arizona.

7.  The Philippines has a population of 91 million.

White sand in Santa Ana, Cagayan.

 Just to give you a glimpse of the place where I was during the last two weeks...

and greetings to you all!

Mystery of the Cyclamen Flower

Most plants that have experienced the summer find rest in autumn as they follow a common earth-tone color.  Red, yellow, orange and brown are normal.  Then there are those radical plants that seem to rebel against this trend.  One unexpected colors of fall comes from the cyclamen flowers.  Not only do they provide a fresh shift from the "dying or resting theme" of those plants that have gone through the rigors of summer, they also provide a renewed crisp life of the season.  Since there are very few varieties of flowers in bloom, I had the luxury of observing this plant more closely than usual. 

Pendant-like blossoms.

The cyclamen flower starts in a droopy position with the end tip of the petals pointing downwards.  The petals are folded in a very organized manner and twisted tightly together forming a beautiful pendant that gracefully hangs on the long pedicel.

The petals turn upward, one at a time.  Flowers exhibiting this tendency are called "reflexed flowers". This phenomenon in directional growth of plant parts can be explained by a differential growth on the opposing surfaces any plant part.  In the case of the cyclamen flowers, growths on the opposite surfaces of the petal are not the same.  The inner surface undergoes a faster cell division or elongation than the other side. 

One petal turns upward at a time.

Reflexed Flower

Flowers are designed in such a way that they contribute to the success of reproduction.  The reflexed petals may seem to make pollination easier than in other plant species since the style is clearly sticking out as seen in the above picture.  One would wonder why seeds rarely form from cyclamen flowers without human intervention.  So I did a little bit of research and found a suitable explanation.  There is an evidence that the stigma is inside instead of the outside the style (Reinchardt S., Ewald F., Hellwig F.).  In normal flowers, the stigma is the sticky part of the flowers where pollen grains would stick to prior to its growth in the style during pollination.  In cyclamen, it is reversed - the style was shown to have a terminal aperture which closes at some point during anthesis thus limiting pollination time. The chemical that controls this opening and closing of the style is not determined at the present.

There's always something new to learn from the garden and cyclamen is indeed an interesting flower!

What's happening in your garden today?

Halloween Tomatoes

Old and sagging.

Pecked with developing pus.

Shrivelled with crusty scab.

Bruised, wounded, and fungus-infected.

Wrinkled and leathery.

My tomato plants need to find their resting place. 

Duck and Duckweed

This park was one of our favorite places to go when the kids were little.  There was a fountain in the middle and the water was really clear we could see small fishes in the water.  The other day I was surprised to see that it is now almost completely covered with tiny little floating plants called duckweeds (Lemna minor).   

Given the right conditions, duckweeds can be very prolific.  One reason for this fast growth in this pond could be high nitrogen content of the water.   The sloped surrounding grass area is kept green year round - meaning high amounts of nitrogen is applied on a regular basis.  It is expected that some nitrogen find their way to the pond through runoff.  A second reason for the high nitrogen content of the water could be due to the animal waste from all the ducks in area.

It appears that the duck population in the area cannot keep up with the growth of the duckweed.  I wonder what the Community Service District will do with this pond - to get rid of the duckweed infestation.  They could keep it that way or do something to remove it so that the water can be clear again.  They could increase the duck population but that will only increase the amount of animal waste going into the water.  They could skim the duckweed regularly but that would be labor intensive.  Duckweed is rich in nitrogen and would make an excellent composting material; local gardeners can be encouraged to do their part and harvest some of the duckweeds. 

Any suggestion?

HortiCOOLture - Spiderweb-like Hair

The Sempervivum arachnoideum is very unique succulent in that it has the appearance of an organized entanglement. If you are not familiar with this plant you might get the impression that they are infested with spiders.  On the contrary, those webby structures on the leaves could be a defense mechanism against insects. 

Trichomes loosely connect leaves together.

The white webs on the leaves are specialized trichomes that connect the leaves together.  As seen from the picture above, there are normal trichomes (hairs) on the surface of the leaves but those that form the webs are coming mainly from the pointy tip and margins of the leaves.  These spiderweb-like trichomes stretch as the leaves grow.  That is why they are increasingly longer and sparse on the periphery of the rosette.  The growth of the trichomes starts with the growth of the leaves as indicated by the concentration of very tight webs in the middle. 

Trichomes are "leaf hairs".    They come in different forms and in some cases there are different types of trichomes in one leaf as exemplified by the Sempervivum arachnoideum.  (Just like in humans and animals - the hair that grows on the head is different from those that grow on the arms, so is in plants.) They have different functions depending on the nature or habitat of the plants.  Trichomes can serve as a deterrent to insects.  Also they can serve as defensive layer against extreme environmental conditions such as wind, heat, cold, ultraviolet rays.  In some cases trichomes also serve as a mechanism for salt tolerance. 

Webby trichomes make the plants look frosty.

Sempervivum arachnoideum is a type of succulent that originated from the Alps (1) and I believe that their trichomes play an important role in its ability to adapt in the snowy, windy and cold conditions of the Alpine Mountains.  It is an evergreen plant and can tolerate freezing temperatures.  Although they do well in dry conditions, adequate water helps the tiny plants to grow at a faster rate. 

Pink flowers float from the multitudes of Sempervivum aracnoideum rosettes.

Sempervivum arachnoideum is a plant to give to an arachnophobe. :)

Happy Halloween!

1) Elijah Walton, Thomas George Bonney (1869).  Flowers from the Upper Alps: With Glimpses of Their Homes

Cymbidium Updates

As of this week, spikes are coming out from the Cymbidium California 'Sun Acres'.  Compared to last year's bloom, these flowers are coming out early.  Considering that we just got into fall season not that long ago, this is indeed a pleasant surprise.  Last year I learned that flower initiation in cymbidiums is greatly affected by the differential temperatures (maximum and minimum) of the day.   They require between 10-20 degrees (F) difference between the day and night time temperatures before flower initiation depending on variety.  Out of the five different cymbidiums I repotted last spring, only this variety is flowering so far.  However, all of them are looking very healthy which indicates that they are all set to put on their own show and just waiting for the opportune moment. 

I intended to pursue cymbidium as my new hobby plant for this year.  My plan was to buy at least 100 plantlets for a start.  My husband, who is always very supportive, already purchased all the pots that I would use for this purpose.  These pots, which are still in a huge box, haunt me every time I see them in the garage. And yet, here I am still vacillating as to whether it is a good idea or not. 

Gardening is a time-sensitive endeavor.  A delay in implementation moves the reward further away.

Parthenocarpy

Parthenocarpic Orange

Par.theno.carpy
Origin: Greek word parthénos = maiden; karpos = fruit)
Literal meaning: virgin fruit
Botanical meaning: enlargement of the ovary into a fruit without fertilization. 
(Parallel meaning: pregnancy without a developing-baby in the womb.)

Parthenocarpy is the phenomenon behind most seedless fruits.  Parthenocarpy is fruiting without the union of a male and a female egg cell.  The lack of fertilization means that there are no seeds in the fruit.  If there are seeds, they are not viable and are not capable of germinating.

Many times we take seedless fruits for granted and even despise the ones with seeds.  Although it is a natural occurrence in some varieties of some plant species (such as banana, persimmon, pineapple, and orange) parthenocarpy is an "abnormal" condition.   I say this because technically fruits are supposed to have seeds.  Seed is the reason for the fruit.  

Seedless grapes with traces of undeveloped seeds.

Fruit development begins with pollination. The moment the right pollen grain touches the stigma (the sticky surface of the pistil), fireworks of events happen as if a switch button has just been set to ON.  First a pollen tube develops as a passage way for the sperm nuclei in the pollen to the reach the ovules (part of the flower that develops into a seed). As soon as the pollen reaches its destination fertilization occurs and a zygote (fertilized egg = seed) is developed. Then several hormonal changes happen to signal a succession of events that support a continued development of the zygote. Gibberellin level suddenly rises resulting in the enlargement of the tissue surrounding the ovary. This tissue eventually differentiates to form the fruit.  Fruits tissues come in different charactreristics:  fleshy (as in grapes, peaches and apples), hard (as in nuts) or dry (as in dandelions and grains).  In short, fruit development occurs when a seed starts to develop. 

How does parthenocarpy happen? 

1.  Uncompleted Seed (Aborted Embryo).  Pollination triggers fruit development but in some cases the embryo is aborted before successfully developing into a seed.   The landing of pollen on the stigma is enough to trigger fruit formation that continues regardless of failed seed development.  Seedlessness through parthenocarpy does not involve fertilization.  However, seedlessness can still happen even after fertilization has already occurred through stenospermocarpy.  In this mechanism, the embryo is aborted just the same but at a much later time (1). The 'Thompson' and 'Flame' seedless grapes are examples of stenospermocarpy; traces of undeveloped seeds are visible when the berries are opened (see picture above).

2.  Genetic Disorder (Chromosome Imbalance).  Plant species which are triploids cannot successfully produce seeds - they are genetically sterile. The banana we buy from the grocery store is parthenocarpic because it is a sterile triploid (two sets of chromosomes from one parent and one set from the other) instead of the normal diploid where you get one set of chromosomes from each parent.  Pollination happens but fertilization does not.  The tiny black dots inside the banana are traces of the unfertilized ovules.  In the case of seedless watermelon, triploidy is induced through genetic manipulation. 

3.  Absence of a Perfect Mate (Self-Incompatibility).  Some plants species are self-incompatible - they are self sterile when pollinated by the same variety of plant.  In order to fruit, these species require pollens from a plant of different genetic makeup.  Navel oranges, pineapples, and clementines are examples of self -incompatible plants.  For example, when an orchard of the same variety of oranges is grown, fruits would come out seedless (parthenocarpic).    

4.  Manipulation by Steroids (Application of Growth-Regulators).  There are several growth hormones that play a role in parthenocarpy but for the current topic, our focus will be gibberellin.  Gibberellin is a phytohormone (plant produced-hormone) that is also produced by certain fungus called Gibberella fujikuroi.  Through this fungus, gibberellin-like compounds known as gibberellic acid (GA) can be produced apart from the plant.  GA is known to promote cell division and enlargement; when applied to plant at a strategic time and rate, the plant will respond accordingly.  This knowledge regarding the response of plants to applied GA and the knowledge that endogenous (produced within) gibberellin levels in plants increase upon fertilization and thus triggering fruit development have changed the horticulture industry.  Flowers can now be fooled into thinking that fertilization has taken place and thereby developing fruit-tissues.  In other words, fruits can be induced with the application of gibberellic acid.

Parthenocarpy is a delightful abnormality because the seedless fruit maintains the appearance and taste of its normal counterpart.  This is the reason why growers have capitalized on it to improve the commercial value of some crops.  Research work continues to exploit the application of parthenocarpy on more plant species where the seed is not for consumption.  

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1) Table Grape Berry Growth and Development: A Review