INTRODUCTION 
xiii 
One other work calls for special consideration. This is Adanson’s Families des Plantes (1763). 
This also is a book which is wholly pre-Linnaean in character although not in chronology, as 
may be ascertained by reading the Introduction to the work. The book deals with genera almost 
entirely ; but the genera adopted are Tournefortian ones and not Linnaean ; and species, on the 
few occasions when they are alluded to, are given pre-Linnaean names and not binominals. 
The book therefore stands in the same category as those above cited of Miller, Hill, and Haller; 
and we accordingly reject the names in Adanson’s book as well as those of the works cited of Miller, 
Hill, and Haller. 
Of course, when these authors adopt binominals, they incorporate so much of the Linnaean 
outlook on botany that they must stand with other works of the post- Linnaean period ; and 
consequently the generic names and the binominals in Miller’s Gardener s Dictionary ed. 8 (1768), 
in Miller’s Abridgment of the Gardener s Dictionary , ed. 6 (1771), and in Hill’s Vegetable System 
( 1759 — 1772) are quite valid. 
Hence several familiar generic names will, in The Cambridge British Flora , displace several 
corresponding less familiar ones which at present appear in British lists of plants ; and in some 
others a change of the authority will be necessitated. 
Species subdivided by Linnaeus 
We deviate slightly from the letter of the international rules in the cases of those few species 
of the first edition of the Species Plantarum, which Linnaeus himself subdivided into two or more 
species in the second edition (1762 — 1763). For these species, we take the second edition as the 
starting-point of nomenclature. Cf. Beta maritima and Salicornia herbacea, p. 168 and p. 191 
respectively of the present volume. 
General rule of nomenclature 
Bearing in mind the points already laid down, the general rule of nomenclature may be 
stated as follows : — The name first given to a group of plants is unalterable so long as the group 
retains the same rank. An exception is made to this rule, where its adoption would lead to 
mere duplication. Thus, the name Castanea castanea for the Spanish chestnut is inadmissible ; 
and the name C. sativa is adopted, although castanea (in Fagus castanea L.) is the earliest trivial 
name for the plant. Similarly (although the rules do not specifically mention this) the analogous 
duplication in names of lower than specific rank is not adopted in this work. For example, 
we should reject the names Populus alba subsp. alba, Populus alba var. alba, and all analogous 
names : we regard the rejection of these names as logically inevitable if such names as Castanea 
castanea are to be rejected, as the rules demand. 
Groups named after a genus 
Orders, suborders, families, subfamilies, tribes, and subtribes are given definite terminations 
which, in the present work, are regarded as absolute ; and orders, and at least one suborder, one 
family, one subfamily, one tribe, and one subtribe should be named after the same genus that 
gives its name to the order when the group in question contains that genus. 
The names of orders end with the affix -ales. The affix is placed after the stem of the 
genus (an existing one) which gives its name to the order. 
Names of suborders end in -ineae. At least one suborder must be named after the genus 
which provides the name for the order. 
Names of families end in -aceae. At least one family must be named after the genus which 
provides the name for the order. 
Names of subfamilies end in -ideae. At least one of the subfamilies must be named after 
the genus which provides the name for the order. 
Names of tribes end in -eae. At least one of the tribes must be named after the genus 
which provides the name for the order if this genus is contained in any of the tribes. 
Names of subtribes end in -inae. At least one of the subtribes must be named after the 
genus which provides the name for the order if this genus is contained in any of the subtribes. 
