182 



MISSOURI BOTANICAL GARDEN. 



able that the latter are real cases of polyphylly and not of 

 synanthy, in which, instead of the partial coalescence of two 

 primordia or their failure to separate, there is a variation 

 in the division of the Anlagen of the various cycles of organs 

 in the flower, resulting in a flower having a larger or smaller 



umber of 



When, as 



droecium is normal while the calyx and corol 

 Tease of Darts, this mav be considered to be 



om 



the 



polyphylly rather than synanthy. 



The ten pentamerous flowers in 0. biennis f 

 Chelsea Physic Garden were found in a culture of 

 33 plants, and careful search would doubtless have 

 revealed further cases. Evidently the phenomenon is rela- 

 tively common in this race. 1 The characters of the race 



nd are remarkablv different from 



of 



They will be de- 



bed 



These 



but one bract at their b 



the phenomenon of pentamery is here due to polyphylly 

 rather than to synanthy, although the fact that one of these 

 basal bracts had a double tin might be considered to favor 



d 



seem therefore 





of synanthy, or coalescence of two primordia, the trimerous 

 flowers and also evidently some at least of the other cases 

 with only one bract at base, are real instances of polyphylly, 

 due to variations in the divisions which the primordia of a 



flower normally undergo. 



My conception of the process of synanthy is that, owing 

 to variations in phyllotaxy, two independent flower primordia 

 become so closely approximated that they partly coalesce, 

 and develop harmoniously into a single flower in a some- 

 what similar fashion to the growth of a plant chimera (sec- 

 torial chimera) as described by Baur and by Winkler. 



Tricotyly. — A number of cases of tricotyly and other 

 abnormalities of the cotyledons have been observed in my 



i Penzig (1890) states that in O. biennis pentamerous flowers are 

 common, the number of "carpels" often running up to 9. 



