Update on rhododendron pollination

In my musings on rhododendron anatomy, yesterday, a few questions about their pollination presented themselves.

Today, I fired up "the Google".

First, why didn't I see pollen on the anthers?

From a discussion of hand-pollination of rhododendrons, I learn the following:

"The stamen consists of the anther, which has two chambers, each with a hole through which the pollen is dispensed. The chambers are called lobes or pollen sacs and contain masses of pollen grains."

Here's that photo, again:
So the pollen is inside those little purple tubes. But there's more:

"Pollen is not a dust as in many plants, but rather long, irregular (tacky) stringy masses. The pollen ripens before the flower opens. After the flower opens, the pollen may soon be lost."

The flowers that I examined had been open for several days. The pollen was long gone. In an anther containing pollen, I should be able to see those stringy masses protruding from the holes. If not, I may be able to shake the pollen out, which is what the bee would do.

The second question was whether the pollen would come from the same flower, or from another.

The stigma (the female receptor, that red tip above) is ready for pollen about three days after the flower has opened. In other words, it will be receiving pollen from another flower, freshly opened. (Pollen can be dried and frozen for later use, but the rhodos aren't up to those tricks. Only human hybridizers do that.)

Rhododendrons and their relatives, the azaleas, hybridize quite easily, as we can see quite easily here in the Vancouver area; there are as many varieties of rhodies as there are backyards, I think.

And I found this fascinating:

"Once the stigma ripens, a critical process must take place whereby the stigma excretes a thin syrup and furnishes nourishment to the pollen which then forms a sprout-like process called a pollen tube. The style (stem) portion of the pistil has a channel running down its center from the stigma to the ovary configured with loosely formed cells through which materials easily pass. The pollen tube grows, heading down this canal. The pollen tube develops into a long slender thread-like structure as it grows down the style canal toward the ovary. At its lower end, the pollen tube contains the male cells and vegetative nucleus. In the ovary, the female (egg) cells are present. After a minimum of 24 hours at approximately 68°F, the pollen tube enters the ovule; the male nucleus is discharge and fuses with the egg nucleus to form a new seed. A separate ovule and a separate pollen cell are required to produce each seed. Dr. Bowers further writes that "up to several hundred pollen tubes may pass down the style at any one time and these may not be of the same variety or species. " Therefore, it is entirely possible in open pollinated flowers for one rhododendron flower to be successfully pollinated by several different sources of pollen at once."

And after all that effort, I come along and deadhead every single stem.