Pollination & Germination

Somehow every explanation of pollination and germination that I’ve seen, beyond the very basics, has been hard to follow, harder to absorb and impossible to retain.  There are so many exceptions to the rules, so many variations, so many peculiar names of the anatomy, that it all seems to become a muddle after a day or so.  They only way I seem to remember things like this is to take them apart, look at the pieces, and put them back together again, so that is what this page is for.


Pollination


In flowering plants, pollination is necessary to reproduction of the plant. Pollination happens when pollen from the anther (male part) comes into contact with the stigma (female part) of the plant. At that point fertilization and reproduction can begin. The flower of the Opuntia, or cactus pear, seems to have all of the main parts on full display, so let’s begin by looking at that.

optuniafloweranatomy

The Anatomy of a Flower. Here an Opuntia cactus flower, to become a cactus pear.

greenbeediggin

Green Halictid Bee digging for nectar behind pistil.

First, there is the pistil.  It sure sounds male but it is actually the female part of the flower.  Normally it is in the center, and the Opuntia flower is no exception.  It’s the soft yellow stem in the middle of the pictures above and to the right.  The stigma, at the top of a pistil, is normally sticky to catch pollen (more on that later), that opens when it is ready (right).  From there the “stem” of the pistil is actually called the “style”.  That leads to the Ovule(s) and Ovary, where seeds for the next generation of the plant will be made.  The ovary also often has tissue on the outer walls called the septal nectary that produces a sweet nectar.  Bees, butterflies, moths and other critters are attracted to it, and in digging down for it, they often help transfer pollen from the anthers to he stigma.

Pollen is . . .

I live in Florida, and it’s been said that all plants are annuals here, because the weather kills them off at some part of the year.  However, a plant like our Opuntia is most definitely a perennial anywhere it can grow, which is to say it lasts more than one or two years (“per” meaning through, “annual” meaning years–so it lasts through the years, where an “annual” normally lasts only one year, and a biennial lasts two years).  Regardless of their lifespan, nature has arranged that the motivating impulse of plants is to reproduce, and they spend a good amount of effort to do so.

some plants don’t pollenate  bananas etc

hybrids

 

mextarragonflowers

Mexican tarragon.

amarillis

Amarillis

 

 

mothpollination

Ceraunus Blue Butterfly on Camomile flower

301633_2190916050264_1689347508_n

Bee on mustard green flower


All color photos and text (c) John D. Pierce, and may not be used without written consent.


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