CHAPTER XX 



AUTUMNAL COLOUR IN TREES AND SHRUBS. 



IN our always uncertain and frequently dull summers and autumns, the 

 colouring of leaves of deciduous trees before they fall can never be 

 counted on, or foretold, to the same extent as in countries where the 

 seasons are more defined in their duration and less changeable whilst they 

 last. The change in the colour of leaves from green to various tints of 

 red, yellow, purple and brown in autumn is due to certain changes in 

 their composition, partly brought about by sunlight, and influenced by 

 other factors, such as moisture and temperature. There is no doubt that 

 a hot summer and a fine autumn induce a richer and more certain 

 colouring in the majority of trees and shrubs than dull or wet ones. Yet 

 after even the wettest of seasons a good deal of autumn colour is always 

 produced. It is possible also to have too much heat and sunshine. In 

 1 91 1, on deep, rich soils, some of the most gorgeous colour effects ever 

 seen among the trees and shrubs in this country were developed ; but on 

 dry shallow soils, the leaves either fell early or were too desiccated by heat 

 and drought for the necessary chemical changes to take place. 



On the whole, trees and shrubs that have passed their vigorous young 

 stage colour better than those producing thick succulent shoots, whether 

 these are induced by youthful vigour or by a specially rich soil in which 

 they grow. 



Acer circinatum, red and orange. 

 ,, cissifolium, yellow and red. 

 ,, japonicum, crimson. 

 ,, nikoense, rich red. 

 ,, palmatum, rich red. 

 ,, rubrum sanguineum, red. 

 ,, Tschonoskii, canary yellow. 

 Amelanchier canadensis, red, sometimes 

 yellow. 



,, florida, yellow. 



Berberis concinna, red. 



Thunbergii, rich red. 



Berberis vulgaris, rich red. 

 ,, Wilsonae, rich red. 

 ,, yunnanense, crimson. 

 Carya alba, rich yellow. 



,, tomentosa, rich yellow. 

 Cladrastis tinctoria, rich yellow. 

 Cornus florida, red and crimson. 



,, sanguinea, red. 

 Crataegus Crus-galli, red and orange. 

 pinnatifida, bronzy red. 

 ,, prunifolia, red and orange. 

 Disanthus cercidifolia, claret colour. 



