I've been watching two trees that hold their fruits all winter - the ash (Fraxinus) and boxelder (Acer negundo).
Their fruits are similar - both are "winged achenes" known as "samaras," distinguished by flattened wings of paper-like tissue that develops from the wall of the ovary.
Botanists describe these fruits as "simple" (the ripened ovary of a flower with a single pistil), "dry" (not fleshy like an apple) and "indehiscent" (they don't open to expel seeds - like a milkweed pod)
When I was a kid we called them helicopters and whirlybirds. Their winged design helps the wind fly them away from the parent trees.
When do these trees "let go" and drop their seeds?
I could look it up, but it's more fun to wait and see. I've been waiting and I've been watching all winter.
The dropping of the samaras started last week...
No comments:
Post a Comment