Tuesday, December 21, 2010

The Bulbophyllum lepidum flowers: Like porn for flies.

Incoming!
My Bulbophyllum lepidum showing several inflorescences

Those flowers look... Hmmm... so alluring and soft and nice smelling

Hey you!  Are you talking to me!

Do you come here often?

Can I buy you a drink?

Your place of mine?  Hey, hey, stop!, stop! !@$%#@$%##^%^%$&$!!!!!!!
 Bulbophylum lepidum is a small orchid that produces inflorescences that resemble half a daisy.  It comes as somewhat of a surprise that a plant in the orchid group will try to resemble a plant in the Compositaceae, the group that includes daisies.  But it all has to do with the need to attract pollinators.  It seems that in this orchid original haunts the local pollinators are strongly attracted to daisies.  Each petal of the “daisy” is an individual orchid flower.  To make things even more interesting the lip of the flowers is hinged and carefully balanced.  If a fly steps on to it, the lip suddenly bends downwards against the column of the flower putting the fly in contact with the adhesive parts at the base of the pollinia.  I have seen unwary flies tumble head first into the flowers of Bulb. lepidum and their reaction never fails to amuse me.
The flowers seem to be mighty attractive to certain small flies.  I have tried to detect what could be so alluring for the flies but so far I have not been able to perceive any fragrance or objectionable smell.  I have to add that the flowers are apparently not attractive all the time, I have only seen activity on them in middle morning.   Whatever attractant the orchid uses to seduce the flies, it is impressively effective.  The flies seem mesmerized by the flowers and become reluctant to fly away from the area.  The fact that my garden is packed with a plethora of reptile, amphibian and arachnid predators that view these insects as flying sandwiches, make this detail even more amazing.   The flies give the impression that they are observing the flowers with the intensity and attentiveness that humans usually reserve to porn, boxing events and lottery drawings.   This disregard for the proximity of potential danger, in which the flies throw caution to the wind, has allowed me to take surprisingly close photos of the flies with my point and shoot camera.  But let’s explain what happens when a fly gets land of a flower.
The flies land on the lip of the flower and then proceed to orient themselves over the long axis of the flower.  Then they slowly move closer to the base of the flower and to the lip.  This may take some time and may be preceded by several flights around the flower as the fly react to alarming stimuli or to other flies buzzing nearby.  Eventually some of the flies step into the lip and are flipped against the column. 
The sudden flip into the column is a startling and frightening event for the flies and you can hear them buzzing loudly and wagging their legs violently.  With only one exception all the flies that have gone through this ordeal have extricated themselves from the flower quickly and flown away with great alacrity so that I have lost them from sight.  On the single case I was able to make observations after the fly had fallen into the flower, I could see the yellow pollinia in the back of the fly.  The fly with the pollinia stood still for a while and then flew away, apparently none the worse for having the pollinia on its back.
Of all my Bulbophyllum this species is the most hardy and undemanding.  It has been growing in the same tree fern pole for the last six years and has covered most of it.  It blooms faithfully for several months every year.  Because it has many pseudobulbs that bloom following their own particular time table the plant has flowers intermittently over a period of months instead of a single flush of many inflorescences at the same time. Each inflorescence last only a few days, they last even less time if they are damaged by strong rain.
My plant is fertilized with 20-20-20 at the rate of one teaspoon per gallon every week during the growing season.  I don’t fertilize if the plant is not producing new growth.
It is grown in what is called “Cattleya light” conditions, which is stronger than for most of my other Bulbophyllums which like more shade, but suits this species fine.  My plant grows better under brighter light and blooms more often.  It gets watered every day when the weather is hot to avoid dehydration.  The rest of the year it can grow fine watered two times a week, but remember I live in a tropical country with a high degree of environmental humidity.
Temperatures locally fluctuate during the year from 65F at night in winter to 95 during the day in the height of the summer.  There is a 10F difference in temperature between the day’s high and low temperatures.

1 comment:

cyber-raga said...

Your blog post is lively and the photos are interesting, especially the one showing the house fly oozing the flower of bulbophyllum lepidum. Keep up the good work!

I also like orchids, especially bulbophyllum. I am going to blogroll yours into my own photo blog.

http://cyber-raga.blogspot.com/