PLAN OF THE FLORA 



The following pages aie devoted to an account of the distribution of 

 the flowering plants and ferns of Berkshire. The species are arranged 

 according to the Natural System, the generic sequence and limita- 

 tions being those of Bentham and Hooker's Genera Plantarum and of 

 Durand's Index to that work. The arrangement, based upon that used 

 by Nyman in his Conspectus, which was employed in my Flora of Oxford- 

 shire is thus departed from, because at present it does appear probable 

 that the former plan is likely to be followed by British botanists, and 

 it is obviously inconvenient to have British floras arranged by such 

 very difl'erent standards. 



The names of the Natural Orders are printed in Eoman capitals and 

 are in almost all cases chosen from the oldest name ending in aceae ; 

 e.g. Cistaceae is chosen rather than Oistineae, and that name is preferred 

 which contains an existing genus from which it is taken. Vihurnaceae 

 is preferred to CaprifoUaceae because a genus Viburnum is extant, but 

 the genus Caprifolium is now merged in Loniccra. The chief exception 

 to the general rule is to be found in the great orders Legumimferae, 

 Umhelli ferae , Compositae, and Grarnineae, which have neither the proper 

 terminations, nor do they include a genus from which the name is 

 formed. These names are now so universally used that I have not 

 attempted to replace them, but I have however given in theee cases 

 alternative names which are in accordance with the rule enunciated. 

 Beneath the name of the Order is placed the name of the Genus printed 

 in heavy capitals. The generic name is chosen according to the law 

 of priority, the starting-point for generic, as well as for specific, 

 citation being understood to be the year 1753 \ the date of the publica- 

 tion of the Species Plantarum by Linnaeus. Generic names therefore 

 which are prior to, but not taken up in that work, only become valid 

 by subsequent publication. The references to the Linnean Genera 

 should be to the fourth edition of the Genera Plantarum, but as I have 

 been unable to consult that edition I have given references to the fifth 



»^ 



1 This date was first proposed by the author in a paper in the Pharma- 

 ceutical Journal, March 26 (1892) 789. 



