Table of Contents

cover image

Volume 24, Number 22
16 November 2005

pp 3831-3983

A beech tree (Fagus grandifolia) and a red maple (Acer rubrum) display brilliant fall colours in the White Mountains, New Hampshire. The yellow is caused by carotenes, the red by anthocyanin left in the leaves after chlorophyll decomposition. The water-soluble anthocyanin�s colour is pH-dependent, causing the brightest red if the sap is slightly acidic. The picture was taken by Julia Schaletzky, currently a PhD student in Tom Rapoport�s Lab at Harvard Medical School in Boston, USA.

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