Stained Glass. Sidney Creek, NC.
Stained Glass. Sidney Creek, NC.

Rounding a blind bend, I entered the deep pool beside the railroad bridge over Sidney Creek and was astonished by the color. It was my first autumn paddling the blackwater creeks of the Carolina coastal plain. The trees were a riot of cinnamon, tan, and fierce orange. I hadn’t expected fall colors in a swamp.

Much of the color came from an unlikely source – a conifer. I had thought all conifers were evergreen. With few exceptions, they are. A notable exception is a bald cypress.

The bald cypress is a mysterious tree. When rooted in muck, it often grows buttresses called knees. Literally, it stands knee-deep in swamp water. No one is certain if the knees primarily support the trunk or allow the roots to breathe. And then there are the fall colors.

Shedding leaves each autumn and beginning over again each spring is a survival strategy. It requires a considerable investment of a tree’s energy to grow new leaves. It pays off only it costs more to maintain leaves year-round.

Trees typically abandon their leaves to conserve water, especially in cold climates where leaves can become desiccated by frost. It may require substantial amounts of moisture to keep the leaves hydrated, putting the entire tree at risk. Dropping its leaves when the weather turns cold, a deciduous tree minimizes the risk.

Dubious Survival Strategy

The average winter temperature on the coastal plain of North Carolina is in the mid-30s. That hardly seems a sufficient threat for a cypress tree to violate the rules of its own phylum and become a deciduous conifer. Why do it? Why become an outlaw?

That’s a good question. I spent hours rephrasing Google searches, even wading into the obtuse nether regions of Google Scholar. I still don’t have a good answer.

Apparently, it’s one of those botanical mysteries. Like the knees of bald cypress.