Flowers of the horsechestnut,Aesculus hippocastanum,a native of the Balkans,and an exotic in the UK. Flowers are borne in large panicles in Spring. Initially,each flower is white with a yellow blotch in the centre. As the flower ages,this changes in hue through orange to a bright red. This is thought to be a result of the fertilisation of the flowers at some time after opening. Many flowers change colour as they age,which may be a signal to passing bees that they have already been pollinated and stripped of nectar by previous visitors. In the case of the horsechestnut,the change from yellow to red is appropriately known as "blushing". The pictures shows a panicle which began flowering a week previously. In each cluster of flowers,the lowest is the most recently opened,and yellow tinted. Older flowers are orange or red |