Nicotiana (26 JAN 2012)

In my first post I wrote :  "This is one of seventeen nicotiana lime green grown from Mrs F's seedlings. Each one grew to maturity and developed its own personality. Had to transplant them several times as I kept underestimating how big they would grow. Think this traumatised them in the summer heat as they would raise their leaves up to cover the inner shoots. They all survived though."

You may wonder why I'm requoting myself after apologising previously for mentioning nicotiana too many times ...

My Blogger Signature Icon  -   August 2010

It's just that Diana invited me to join her meme about our signature plants :
http://elephantseyegarden.blogspot.com/2012/01/my-new-signature-plant.html
(It would be rude not to, and I can't lie to Diana ...)

Seeds were nominally "lime-green" but flower shades faded to white - September 2010

Red nicotiana is also available which fades through pink to white, but there's something about lime-green that makes my heart beat faster.

My pride and joy in my first year of gardening, this abundant display was produced from six tiny seedlings with the aid of a carefully chosen camera-angle ...


Nicotiana rules - October 2010

The joy came to an abrupt end when the first frost was laid in late October 2010. I thought (mistakenly) that the black dots at the centre of the blooms were seeds and stored them in envelopes to dry, they were actually anthers. In autumn, I sowed the "seeds" using my tried-and-tested technique of poking a pencil into the soil, dropping in a couple of seeds, patting soil on top and leaving them in the plastic greenhouse to germinate. Then I discovered that the flower-holders attached to the stalks dried into seed-pods after the flower withered. I sowed these seeds too, unsuccessfully. (I learned later that nicotiana seeds need light to germinate.)

While weeding in June, I recognised a cluster of leaves that brought back happy memories, just as seeds in a seed tray more often than not all germinate simultaneously. The plantlets were separated carefully and transplanted. Did I imagine that these specimens were even more beautiful than their predecessors?  As the summer progressed I found more peer groups, germinating at different times in the subtly different micro-climates around the garden, extending the flowering period well into winter.

June 2011

August 2011

The leaves and stems of nicotiana alata are sticky due to excretions of poisonous nicotine aimed at discouraging herbivores from eating them; these are ornamental plants.
Nicotiana tabacum is grown commercially for the tobacco industry. Not surprisingly, this hyrid can't be found naturally in the wild.


   

My Signature Plant : Nicotiana Alata Lime Green   -   September 2011



Glad it's still around   -  January 2012



Seed-pod remains after the flower has fallen  -  January 2012

When I inspected these nicotiana seeds, I wondered if they all had the potential to grow as their parents, considering my failure to propogate them last year. I wasn't sure if the existence of a seed meant that pollination had taken place. Are plant seeds produced anyway, like unfertilised chickens' eggs ? 

Do all seeds have the potential to germinate if exposed to the right conditions ? - I think the answer is No, because some seeds may not contain embryos. Fertilisation does not occur automatically when pollination takes place (this is what I thought till this week). There is a sequence of events which involves the pollen grain germinating into the stigma, growing a pollen tube down to the ovule at its base, releasing two sperms down the tube which shoot out onto the ovule, double-fertilising to produce the food for the developing embryo (thanks to one sperm) and the embryo itself (thanks to the other).

It's quite amazing that pollination occurs at all considering the number of other flowers a bee could choose to visit, even more amazing when double-fertilisation produces viable seeds.
Incredible that those seeds fell on soil exposed to the right amount of sunlight and moisture to trigger germination, when you think of the efforts we go through in our kitchens or greenhouses to simulate this.
Awesome that my flower-beds were graced with these self-propogating lime-green delights for the past two years and hopefully for many years to come.


Nicotiana seeds should be sown on the surface of the soil as they need light to germinate :
http://www.finegardening.com/plants/articles/flowering-tobaccos-light-up-garden.aspx

Articles about seeds and seed starting :

http://tomclothier.hort.net

Intricacies of post-pollination processes :

http://simple.wikipedia.org/wiki/Pollen_tube


Another definition of ... SIGNATURE : a feature in the appearance or qualities of a natural object formerly held to indicate its utility in medicine either because of a fancied resemblance to a body part (as a heart-shaped leaf indicating utility in heart disease) or because of a presumed relation to some phase of a disease (as the prickly nature of thistle indicating utility in case of a stitch in the side)  ... Meriam-Webster Medical Dictionary
http://www.botgard.ucla.edu/html/botanytextbooks/economicbotany/doctrine/index.html

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