Holding their tan leaves through the winter until spring, American Beech (Fagus grandifolia), is one of a few trees around here that are marcescent. Others include Oak, American Beech, Hornbeam, Eastern Hophornbeam, and Witchhazel.

Marcescence is a name that scientists have given to the process which they have described in detail, explaining what happens. But they haven’t come up with an answer to the question, “Why?”

Normally, in a tree that will lose its leaves in the autumn, the leaf will fall when a layer of cells between the end of the stem of the leaf, and the tree branch is formed. This is the abscission layer, and happens in the autumn. This whole process, in trees that are marcescent, happens in the spring. Those marcescent leaves do not have the abscission layer until the spring, and therefore will not drop until spring.

Through the winter, with its marcescent leaves hanging on, the American Beech makes me think of shave ice as its leaves collect snow as it falls.

And until I hear that scientists have come up with an answer, I will be wondering, “Why?”