Why we're seeing pink maple helicopters and samaras in Chicago

This spring I've been delighted to see so many maple trees dropping lovely pink samaras (aka maple tree helicopters) instead of the usual green ones.

Why it matters: Facebook friends are reporting the same mysterious change across the city and suburbs, but no one really knows why.

Context: Experts note that some trees — especially red maples — produce pink samaras, but they're not quite sure why so many maples would switch from green to pink this year.

The theory: When I reached out to The Morton Arboretum, Openlands and Chicago Botanic Garden, the best guess came from Openlands senior forestry program manager Tom Ebeling.

• He conjectures the pink ones could be coming from a silver and red maple hybrid called a Freeman that can produce both green and pink helicopters.
• And maybe, after this warm dryish winter and spring, "something in the climate is encouraging them to show their pink cards this year."

The request: If you're a tree specialist with further insight, please write to chicago@axios.com and help us out.

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