Thursday, March 8, 2018

Spring Flowers

It's the time of year when the trees come out of dormancy, and we start to see a variety of flowers.

Some are accompanied by strong fragrances, like the orange blossoms and the chaparral sage.
Some are barely visible, like the olive and jojoba.  Two of our jojoba bushes turned out to be female.  You can see the unassuming bell-shaped female jojoba flowers in the picture on the right below.

Others are more showy, like the blackberry and banana.

But I think my favorites this year are the avocado flowers.  They're small and somewhat camouflaged, but the fascinating thing about these flowers is the way they ensure cross-pollination.  All of the flowers  are perfect (having both male and female parts), but the anthers and stigmata open at different times over a two-day cycle.  All the flowers on a single tree enter the male phase - when they release pollen - at the same time.
The yellow parts are nectaries, which provide the payoff for pollinators.  I'm guessing that's what the ant is after.

Below is a flower from the same tree, but at a later time.  Now all the flowers are in the female phase, when they are receptive to pollen.
While this cycle might seem to make it more difficult for a single organism to reproduce, it benefits the population by encouraging genetic diversity, which gave the species more resilience in the wild.  This is a fuerte avocado tree.  Nearby is a Hass.  The Hass avocado tree has a complementary two-day cycle, so it will hopefully cross-pollinate well with the fuerte.

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