XII INTRODUCTION 



Names and formulae of hybrids 



This supplement, like the « Index Pilicum » and the previous supple- 

 ments, comprises also names and formulae of hybrids. The names of hy- 

 brids are preceded by the multiplication sign ( x ) ; the formulae consist 

 of the names of the parents connected by the multiplication sign (x). 



Usually, when hybrids are designated by names, the parents or puta- 

 tive parents are indicated in the form of a formula, which, however, has 

 no nomenclatural value since it is given by the author as a statement of 

 the parentage that is not intended to constitute publication from the no- 

 menclatural point of view. These formulae are quoted in the supplement 

 as cross-references without authority, in different type and separated from 

 the pertinent names by vide instead of =. I have given the cross-references 

 in this way in order to show that they are not true formulae and at the 

 same time to establish clearly that I do not intend to publish them as 

 formulae. They are to be regarded merely as cross-references. 



Bigeneric hybrids 



Bigeneric hybrids designated by a generic name and properly described 

 are treated as the other genera ; their names are printed in bold-face ca- 

 pitals, but preceded by the multiplication sign. They are followed by the 

 name of their author, place and date of publication, and by the formula 

 with the names of their parents printed in italics and placed in square 

 brackets. The cross-references to them are given by mentioning the for- 

 mulae of the generic parents followed only by bigeneric hybrid names. 

 These formulae are prmted in italic capitals. 



designated 



° J ^/^xu.3 vicoiguciLcu. uy a generic name our noi properly aes- 



cribed, or not described at all, are likewise listed with their generic names 



preceded by the multiplication sign and foUowed by full citation and by 



the formula of their generic parents. However, the indication [nomen] is 



added before the names of the parents and moreover, their names are 



printed in italic capitals instead of bold-face capitals. The cross-references 



to them are given by the formulae of their generic parents {in italic capitals) 



followed by the word vide, the bigeneric hybrid names and the indication 

 [Tiomen]. 



Hybrids between species 



Hybrids designated by a name and described in Latin are treated as 

 any other specific epithet. However, they are provided with indications of 

 the parents by the formulae printed in italics, placed in square brackets. 

 The cross-reference to these names is printed in italics and foUowed by 

 the word vide and by the corresponding binomials. 



Some hybrids designated by a name are not described but are based 

 on formulae which are properly established like any other validly published 

 name ; hence the name of the hybrid is validated by the mention of the 

 lormula. In this case the name, in bold-face, is treated as any other specific 

 name, but preceded by the multiplication sign and followed by author, 

 roll citation and reference to the formula which validates it. The cross- 

 reference to these names is given in the supplement by listing the formulae 



