senescence
seh-NESS-ents
The process of aging and decline — in ecology, specifically the process by which leaves change color and fall. Senescence is what happens when a tree withdraws chlorophyll from its leaves before winter, revealing the yellows, oranges, and reds that were hidden beneath the green all along. The colors of autumn are not added; they are uncovered.
Etymology
From Latin senescere, to grow old, from senex, old. The same root gives us "senior" and "senile." In the leaf, senescence is not decay but preparation — the tree is reclaiming its resources before letting go.
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