INTRODUCTION. 
upon the knowledge that the treasures we possess are but a tithe 
of those that we may some day come to have. And, since cata- 
logues each year are helping us to fill these voids, it became obvious 
that such a book as this, to have more than ephemeral value, 
must run ahead of collectors, and give authoritative notes, not 
only on all species that are grown, but also on all such as ought 
to be. In other words, I set myself to peruse my authorities, 
not only with a view to dealing fairly by the plants we know, but 
also to anticipating many catalogues as yet unborn, by discovering, 
through a veil of cumbrous Latin, any promise of beauty in species 
that we do not possess. So that in future, when confronted with 
the offer of a beautiful unknown, collectors may be able to refer 
to this volume, there to ascertain whether indeed it be beautiful 
orno. That such a guide is complete, or ever can be, I should, 
of course, be the last to claim: at the same time it cannot but be 
that this book will be able to make accessible a large amount of 
information on plants and matter hitherto unknown or buried 
in learned works of difficult attamment and digestion. But if 
you were to compile a full list of all plants possible for the rock- 
garden, whether good or bad, no library would hold the number 
of volumes to which such a work would run. Therefore (seeing 
that I have already exceeded the space allotted me by exactly the 
same amount again) my work has had to be severely selective, 
and my own personal taste must be held responsible for many 
omissions; while yet others will have been due to oversight, or 
to the inability of a botanical diagnosis to give any fair notion 
of the beauty belonging to the plant it frigidly describes. 
Some authorities, indeed, are far more helpful than others: 
Boissier’s Latin, for instance, never fails to give a picture and 
convey a thrill, while Ledebour’s descriptions of his species are 
so arid and colourless that no idea can be conjured up of the species 
they classify. Yet when all is said and allowed for, I hope that 
the following pages will be found a really trustworthy guide, 
within their limits, not only as regards the plants we do grow, but 
also to those we may reasonably want to grow. Where beauties 
have been omitted, they will usually be found to be secondary 
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