The
Cassia fistula tree in my yard has
finally lived up to its nickname, Golden Shower.
I
planted it from a seed I was given by a friend quite a few years ago, without
knowing much about it. It grew pretty quickly, but didn’t produce any flowers.
I guess I had planted it too close to a mango tree, so it probably got overshadowed,
and had to grow tall to try to get more sunlight. Then Hurricane Irma removed
the mango tree.
I
first noticed the tree was flowering when I heard bees humming above my head. I
was thrilled when I looked up and saw the first delicate yellow blossoms
trailing down. The dangling flowers are so dramatic you can easily see why
people wanted to transport the seeds from Asia.
Even
though it is not native, the local carpenter bees seemed quite enthusiastic
about visiting the flowers. I have often seen these large, shiny black bees on
other flowers, but never so many at once.
As
they left the tree, the bees all flew off in the same direction, so I thought
they might have a hive over that way. When I read about them, though, I learned
that was wrong. These are actually ‘solitary’ bees, meaning they don’t live in
organized hives like the ‘social’ bumblebees and honeybees.
Still,
they might have been nesting in the same area. The female carpenter bee bores a
hole into dead wood and makes small chambers inside where she places her eggs.
She doesn’t eat the wood, just tunnels into it. She puts one egg in each
chamber, with a rolled up ball of pollen and nectar. Then she seals over the
entrance. If the nests from different bees are close together, the young bees
will be close to each other when they emerge, which is convenient for
mating.
Another
thing I got wrong was thinking that all of the local carpenter bees are black.
In fact it’s only the females. The males are a rusty orange color all over. I
have never seen any bees like that, maybe because the poor things die right
after mating.
Then
I was confused because some of the black bees had yellow on their backs. What
was that about? Were some of them bumblebees? That didn’t make sense.
Finally
I decided that the yellow on their backs was actually pollen from the
flowers.
At
first, the flower buds are like round yellow balls. Then the petals flip back
and the reproductive parts of the flower are exposed.
The
female part of the flower is a long, curved green tube. It is located very
close to three yellow male stamens with pollen sacs on their tips.
For
the brief moment the bee is at the flower, its back comes in contact with those
three pollen sacs.
As
the bee buzzes, pollen gets deposited on its back, giving it a yellow
stripe.
A
few minutes taking photos in the yard had now led to many hours of research on
trees and bees and the intricate ways flowers are structured in order to get
themselves pollinated. My reading included references to Charles Darwin, and
how in his later years he spent a great deal of time in his garden making
observations to expand his understanding of evolution.
It
was fun to feel a link to Darwin, no matter how slight. But also nice to know
you don’t have to be a great scientist to look at bees and flowers in the yard
and learn a little bit about them.
