Seasons, senses & self: Day 25
Trees and shrubs, green all summer
now burst into flamboyant colour,
a pallet of yellows, oranges, red.
When days were brighter and longer,
a powerful pigment, green,
intercepted bright power to manufacture
sugars from water and air, which run
in the sap through the veins, into the phloem
under the bark. Trees grow.
Days shorten; sun weakens. Photosynthesis
tails off and shuts down. Chlorophyll
molecules split apart for recycling;
its dominant green fades away.
Long hidden colours emerge:
yellow flavonols, orange carotenoids, anthocyanins
purple or red. Abscisic acid triggers
a seal at the base of each leaf
and it falls.
Image: Masaki Ikeda