( 801 ) 



the bisexual one until now only in Flanders^) and in this country ^). 



So it is not at all unlikely that of those species whicii until now 

 are known as bisexual only, later other forms will also be found, 

 and similarly it may be assumed that of the large number of Um- 

 belliferae of wliieii now only the monoecious form is known, on 

 closer examination also tiie hermaphrodite or unisexual forms will 

 be found. 



JMeanwhile it is a very reniarkal)le fact that by far the most 

 Umbelliferae are andro-monoecious and that exactly these forms are 

 most generally spread. 



Where male individuals are found they only occur in very 

 limited numbers as rare occurrences among the great majority of 

 andro-monoecious individuals. 



This also holds for the hermaphrodite plants, at any rate for Dauciis 

 Carota, Sium latlfoUum and Heradeum Sphondylium. Where these 

 and andro-monoecious plants occur together the number of biscxuals 

 is far less than that of the andro-monoecious ones. ') 



This general occurrence of andro-monoecious forms gives a very 

 peculiar character to the family of tiie Umbelliferae. Nowhere in 

 the vegetable kingdom these forms are so prominent as here. 



In other families with species that are rich in forms, as the 

 Lahiaiae, Alsineae, Sileneae and others, where gyno- and andro- 

 monoecious and female and male forms occur together with bisexual 

 ones, a similar preponderance of monoecious plants is not found 

 with a single species. 



Tlie rule is there that where the three forms occur together the 

 monoecious flowers are a minority with respect to the bisexual and 

 unisexual ones. 



Next is conspicuous with the monoecious Umbelliferae the great 

 variety that may be observed in the occurrence of the male flowers 

 in the umbels of different order and the man^^ mutually different 

 forms in which consequently' one and the same andro-monoecious 

 plant may occur. 



Sometimes an individual is found which among the large number 

 of bisexual flowers has a relatively small number of male ones, 

 another time one in which the number of male flowers is not much 



1) J. Staes. De blopmeu van Daucus Carota L. Botanisch Jaarboek, Dodonaea 

 Jaargang I. ]889. p. 132. 



-) I shall soon treat elsewhere the different forms in whicli the Ümbelüferae, 

 occurring in this country, are met. 



3) Male Umbelliferae and exclusively bisexual species are very rare also outside 

 Europe. (See Drude Umbelliferae. Enoler und Prantl. Die natiirl. Pflanzenfamilien 

 III. Tell. Abt. 8. p. 91). 



