Memories of last summer

Marcescence: Hanging on

Deciduous Oak and Maple from 2013
in snowshoe track.

At this time of the year, most of the deciduous leaves have fallen to the forest floor. Here at Spiritwood, we have both red and white oak trees. Although Quercus (oak) leaves are tenacious, they don’t cling on to their twigs as resolutely as do beech leaves (Fagus).

The reason beech and oak do remain on their twigs longer, however, is because of a phenomenon called Marcescence. Wikipedia tells us this is “the retention of dead plant organs that normally are shed.”

The online free encyclopedia continues, “It is most obvious in deciduous trees that retain leaves through the winter. Several trees normally have marcescent leaves such as oak (Quercus), beech (Fagus) and hornbeam (Carpinus). Marcescent leaves of pin oak (Quercus palustris) complete development of their abscission layer in the spring. The base of the petiole remains alive over the winter. Many other trees may have marcescent leaves in seasons where an early freeze kills the leaves before the abscission layer develops or completes development. Diseases or pests can also kill leaves before they can develop an abscission layer.”

Soon, I will go outside and get a photo of marcescent leaves of American Beech. This image, however, shows deciduous maple and oak leaves, which have fallen into our snowshoe trail.