3a INTRODUCTION 



sometimes apparently absent (Thuringia and Riesengebirge) or occurring sporadi- 

 cally (Tyrol) : perhaps more abundant in North Europe. 



Erodium cicutarium. Female-pleogamous 5-30 % ; male forms scarce and 

 isolated. 



Valeriana montana. Mostly gynodioecious, frequently also gynomonoecious. 

 Isolated S plants, or, rarely, S and ? on the same plant. 



Polygonum viviparum. Female-pleogamous up to 30 % ; male-pleogamous 

 usually only 1-2 %, never more than 10 %. 



P. Fagopyrum. Gynomonoecious up to 20 % ; sporadically gynodioecious, 

 andromonofecious, or androdioecious. 



Thymus Chamaedrys. Gynodioecious up to 40-50 %, or even more ; very 

 seldom gynomonoecious; observed by Ogle in England and Delpino in Italy to 

 be also androdioecious. 



Viscaria vulgaris. Usually gynodioecious, seldom gynomonoecious; ? in 

 some localities up to 20 %. Male pleogamous forms, when present, only 2-5 %. 



Coronaria Flos cuculi. Gynodioecious, seldom gynomonoecious up to 10 % at 

 most. Male-pleogamous forms at most 3 %. 



Silene rupestris. Gynodioecious and gynomonoecious up to 5 %. Male- 

 pleogamous forms very scarce. 



S. nutans. Female forms up to 10%; male (if present) up to 5 %. 



Saponaria ocymoides. Gynodioecious or gynomonoecious forms up to 5 %. 

 Male-pleogamous forms very scarce. 



(J>) Male Forms predominate. 



Daucus Carota. Andromonoecious, frequently also gynodioecious, seldom 

 gynomonoecious. 



Pimpinella Saxifraga. Andromonoecious, less frequently gynodioecious. 



Scleranthus annuus. Male-pleogamous widely distributed, usually 5-10%; 

 female scarce and isolated. 



Pulsatilla vulgaris, montana, pratensis, and vernalis. Occasionally andro- 

 monoecious and androdioecious, now and then also gynomonoecious and 

 gynodioecious. 



{c) Female and Male Forms about equally common. 



Scleranthus perennis. Female-pleogamous forms widely distributed, often 30 % 

 or more ; male, if present, numerous. 



Silene vulgaris. Gynodioecious; less frequently gynomonoecious, sometimes 

 only 1—2 %, sometimes 50 % or more. In plains, fairly often androdioecious ; with 

 wide distribution ; less frequently andromonoecious, S often up to 20 %. In 

 mountains, S forms are often wanting. 



S. noctiflora. Gynodioecious, forms widely distributed, gynomonoecious less 

 frequently. J forms unequally distributed, rare in places. 



Valeriana tripteris. In South Tyrol usually gynodioecious and gynomono- 

 ecious ; locally andromonoecious and androdioecious, sometimes even ? and J, or 

 5 , ? , and S on the same plant. 



