From Flowers To Beans

On 29 August I posed the question “How do wild senna flowers become shiny green bean pods?” Last week I decided to find out.

Wild senna (Senna hebecarpa) flowers grow in bunches on a tall stem.

Each flower holds the secret to the bean. In the closeup below you see irregular yellow petals, stamens with brown anthers, and a tiny green stem with fuzzy white edges — the pistil. Instead of a single ovary at the base of the pistil there’s apparently a row of ovaries inside.

When the flower is fertilized, the yellow petals fall off. The stamens and pistil remain.

As the fuzzy green pistil grows the anthers fall off

Though still fuzzy, the former pistil begins to look like a bean pod.

The remaining twigs fall off, the bean pods lose their fuzz and Ta Dah!

Wild senna gone to seed (photo by Kate St. John)

The secret is that row of ovaries.

(photos by Kate St. John)

3 thoughts on “From Flowers To Beans

  1. excellent play by play. Can’t wait to go out to the park and look for one in person. Thanks Kate. I hope to follow your lead and downsize too one of these days. Hope your settled in. Best Wishes to you.

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