Taken: 4 July 2021
Notes: Before shedding their summer canopy, deciduous trees strip their own leafage of nutrients, consolidating the valuable resources in root systems for winter. However, some chemicals continue to remain with the fleeting matrix of expiring leaves - as chlorophyll and carotenoids drain, tannins (which serve as a means to fend off predation), colour the foliage an autumnal brown. When the decaying cells of fallen, rain-soaked leaves inevitably rupture, the rusty-brown pigmentation of exposed tannins begin to run onto urban surfaces. The disintegrating leaf is then carried off (either by the wind or by human intervention), and dark impressions on porous concrete slabs remain.