This Garden Vocabulary series seeks to introduce and explain to you — and in many cases, myself — words and terms associated with gardening. Please let me know if there are any terms you would like me to explore. You can leave your ideas in the comments section and we can learn together!
“Deciduous means “falling off at maturity” or “tending to fall off”, and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe. In a more general sense, deciduous means the dropping of a part that is no longer needed, or falling away after its purpose is finished. In plants it is the result of natural processes. Deciduous has a similar meaning when referring to animal parts, such as deciduous antlers in deer, or deciduous teeth, also known as baby teeth, in some mammals (including human children).”
Wikipedia, Deciduous, http://en.wikipedia.org/wiki/Deciduous
This is one of the first concepts you learn in basic school science classes, deciduous vs. evergreen. Even then, though, there are levels of subtly between these two levels. Here in California we have Live Oak trees which never lose all their leaves at once, but according to the definition above, they would be classified as deciduous. We tend to think that deciduous means those trees and plants that lose their leaves in Winter, but in our climate there are many deciduous trees that don’t.
Until researching this entry, I didn’t realize that the term applied to mammals as well.
Further reading on Deciduous: