Leaf Marcescence

Some deciduous trees retain their leaves through the winter.

Normally in autumn a breakaway layer called an abscission zone forms at the base of the leaf petiole and the leaf drops to the ground.   

But it doesn't always happen that way. When it doesn't, the phenomenon is called leaf marcescence. 

According to forest ecologist Lars Brudvig, "Leaf marcescence is common for a number of tree species - most notably American beech and the oaks, but also ironwood, witch hazel, and others." 

It's more common in younger trees—or the younger parts of trees.

"Note that retained lower branches on large trees started growth when the tree was young - so, lower branches can keep 'juvenile' characteristics, like marcescence."

--

Photos and quotes thanks to Lars Brudvig (@lars_brudvig on Twitter)

·