DISTRIBUTION OF SEXES 33 



Poterium Sanguisorba. Usually J , 5 , and $? on the same plant, occasionally 

 also gynomonoecious, or andromonoecious, or purely monoecious. 



Rumex maritimus and other species. Frequently gynomonoecious, less frequently 

 gynodioecious. Sometimes purely $ and ? stocks. 



Alchemilla vulgaris, fissa, alpina, and pentapetala. Male- and female- 

 pleogamous forms locally replace hermaphrodites. 



3. Dioecism predominates ; the sexes about equally well represented. Hermaphrodite 

 and pleogamous forms are not numerous. 



Silene Otites and acaulis. Almost exclusively dioecious. 



Melandryum album. Dioecious. J and ? equally common. Hermaphrodite 

 forms very rare. 



M. rubrum. Usually dioecious. J and $ sometimes equally common, 

 sometimes one (generally 5 ) predominating. Hermaphrodite plants commoner 

 than in the preceding species (often up to 5 %). Sporadically monoecious, very 

 rarely andromonoecious. 



Fragaria elatior. In some places dioecious, in other places purely hermaphrodite 

 flowers (up to 10%); in places only female- and male-pleogamous, often gyno- 

 monoecious ; on the other hand, andromonoecious individuals are occasionally 

 altogether absent. 



Rubus Chamaemorus. Dioecious. In the Riesengebirge sometimes almost 

 completely falsely hermaphrodite. 



Valeriana dioica. Usually dioecious, 5 usually in two forms ; ^ rare and 

 local. 



V. saxatilis. S and ? plants equally common, ^ sporadic ; may also be 

 andromonoecious and gynomonoecious, frequently $ and J , rarely $ , J , and 5? 

 on the same plant. 



Trinia glauca. J and $ plants about equally common. Various pleogamous 

 forms occur locally. 



Rumex Acetosa, Acetosella and arifolius. 5 and ? plants equally common, 

 rarely gynomonoecious, or andromonoecious, or hermaphrodite. 



Rhodiola rosea. Dioecious (in the Riesengebirge according to Schulz, on 

 the Dovrefjeld according to Lindman) or trioecious (in the Alps according to 

 Ricca, in Greenland according to Warming). 



Empetrum nigrum. In the North Frisian Islands trioecious, with very rare 

 hermaphrodite forms (Buchenau), similarly on the Dovrefjeld (Lindman); in 

 Greenland only dioecious (Warming). 



Asparagus oflficinaHs. Usually dioecious ; rarely purely hermaphrodite, andro- 

 monoecious, and gynomonoecious plants. 



The above-mentioned investigations, undertaken by Schulz with great care and 

 perseverance, still require much amplification to make them complete. On this 

 point Loew (' Bliitenbiol. Floristik,' p. 392) remarks that 'Progress in this sphere 

 is only possible by correlated and systematized work, conducted by many 

 investigators.' 



