Yellow Flower in Tree – Cassia or Senna sp.?

For the past couple of weeks I’ve been admiring the yellow flowers in a tree near the quebrada – the seasonal spring at the edge of our property. I’ve finally looked at it long enough and closely enough to believe it is a species of Cassia or Senna, but the number of stamens (4) suggest not. It looks very much like the tree known commonly as Scrambled Eggs, but it is definitely not the same species. Here it is, resting on the stone wall in front of the tree itself. 

The tree is in a “tangled bank” of vegetation so it’s not easy to get a simple picture of the tree. Here’s the best I could do.

After I clipped away a few branches of other trees for a better view, I was able to get a look at the bark.

 

Here are the flowers on the tree.

 

And here are the leaves (scanned):

Here’s why I don’t think this is the Cassia surattensis or Scrambled Egg tree. A nice image from the Ruhr Botanical Garden shows 8 or 9 stamens, with 2 of them dropped away from the rest of the group.

My flower has only 4 stamens and they are grouped tightly together, so tightly that at first I thought they might be fused.

 

Here’s the center of the flower seen through a hand lens.

And here’s a scan showing one flower (upper right) where the 4 central stamens have dropped off, revealing some stub-like features that may be staminoids.

I’ll keep on looking, but meantime, anyone who knows what this species is, please let me know. It’s a great little tree.

Update: This tree has been identified as Senna hayesiana. More about the ID here and some biology here.

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One Response to Yellow Flower in Tree – Cassia or Senna sp.?

  1. Pingback: Senna hayesiana in bloom | A Neotropical Savanna

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