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 denned 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 line  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

1911, 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.

    „       fiorida, yellow.

Berberis concinna,  red.

   „   Thunbergi, rich red.

         7y
 

Berberis vulgaris, rich red.

   ,,   Wilsonse, rich red.

   ,,   yunnanense, crimson.

Carya alba, rich yellow.

  ,,  tomentosa, rich yellow.

Cladrastis tinctoria, rich yellow.

Cornus fiorida, red and crimson.

   ,,    sanguinea, red.

Crataegus Crus-galli, red and orange.

    ,,     pinnatifida, bronzy red.

    ,,     prunifolia, red and orange.

Disanthus cercidifolia, claret colour.