CHAPTER XI
 

                   Evergreen Trees and Shrubs.



In  no class of outdoor plants is our  indebtedness to the floras of other

countries  so evident as  in. the case  of  hardy evergreens.  The broad-

leaved evergreens, as distinct from conifers, represent a type of vegetation

which is essentially a tropical  and subtropical one.  As  one gets farther

from the equator  their gradual  displacement by deciduous vegetation and

conifers becomes more and more marked.   In Great Britain we  have the

box, the holly, the yew, the Scotch pine,  common juniper, gorse, various

heaths and other  low shrubs, and the ivy.    In S.W. Ireland these have a

remarkable addition  in Arbutus  Unedo, the strawberry tree.

    Conifers and  dwarf, small-leaved evergreens of the heather, crowberry,

and Vaccinium  type  are some of the hardiest plants  of  the  globe.  But

most of the  choice evergreens  of the garden type—broad-leaved trees, or

shrubs too tall  to be covered  by snow in  winter—are dependent for their

welfare on two conditions, viz., an  equable climate  and an abundance of

moisture at the root  and in the atmosphere.  They will  always  be found

most abundant, both in nature and under  cultivation, where the rainfall is

greatest and the climate free from great extremes of heat and cold.  Our

islands, especially on the western side, afford conditions better  adapted

to their cultivation than perhaps any other part of northern Europe  of

similar extent.  Japan with its  insular climate, and western  S.  America,

bathed  with moisture from the  Pacific,  are  both   singularly  rich  in

evergreens.

    Four of  our native evergreens still hold a position  of supremacy in

spite of the number of their foreign rivals.   These are the holly, yew, box,

and ivy, each of which fills a place in gardens no exotic evergreen could

occupy.   With  regard to the ivy, it  is a  singular fact that it is still  not

only the best, but practically the only genuinely hardy climbing evergreen.

The scarcity of evergreen climbers in gardens has been but little relieved

by  recent exploration in China and elsewhere.   Their  meagre number

in  cool temperate regions  is  even more  marked than that  of  bushy

evergreens.

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