Hand pollination

Michael Mace michaelcmace@gmail.com
Mon, 30 Oct 2017 08:50:21 PDT
Jane wrote:

>>> How does one tell when the flower's reproductive parts are mature? I can
Tell when the pollen is dehiscing, but I don't know when the stigma is
receptive. In many plants, the two processes occur at different times to
avoid self-pollination. Is there some visual cue to this?

Usually yes, but the visual cue varies by genus.

Generally you'll be able to spot a physical change in the surface of the
stigma. The end may go from smooth to rough, or the tip may split, lengthen,
or become feathery. The best advice I can give you is to check the flowers
every day and watch the stigma. After a bit you'll spot the change and it'll
become obvious.

Often the change is pretty obvious once you know what to look for. In
Amaryllis, tip of the stigma splits into three and the ends look fuzzy. On
the other hand, with Brunsvigias (another Amaryllid), the stigmas never seem
to change and I have to guess when they are ready.

In Moraeas, the stigma is often a little flap, and as long as you can pry it
open and shove some pollen in there, it doesn't seem to matter when you do

In Calochortus, the stigma starts off smooth and shiny looking. When ready
for pollen, the three parts of it (the stigmatic lips?) widen and flatten
and have a slight fuzz to them, like velvet. Many Tulips are similar.

(I should add that I think these changes are linked to pollen receptivity,
but I haven't done controlled experiments to prove it. I remember once when
I talked with an experienced Amaryllid breeder, I asked him about checking
the flowers for receptivity before pollinating them. He said something to
the effect of, "I pollinate them whenever I can, multiple times if possible.
I figure that gives me the best chance of having pollen there when the
flower becomes receptive.")

Hope that helps.

San Jose, CA

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