1 8 Rhodora [January 



THE PSEUDO-MONOCLINISM OF CHIONANTHUS 

 VIRGINICA. 



Alfred Rehder. 



Some years ago ChionaJithiis Tirij^ifiica, which though not native 

 to New England is often cultivated for its ornamental qualities, 

 attracted my attention by some peculiarities in its fruiting and flow- 

 ering. I noticed that the shrubs in bloom presented noticeable 

 differences in their appearance and that some shrubs bore fruit 

 abundantly, while others had no fruit at all. An examination of the 

 flowers of several shrubs showed some difference in their structure 

 and as I could not remember any notice of it in botanical literature,. 

 I decided to make a closer investigation. I examined carefully the 

 flowers of all the shrubs of the species growing in the Arnold Abore- 

 tum, of which 14 were planted in one group together, while one 

 shrub was standing solitary some distance away from that group. I 

 marked them all with numbers and took notes on the structure of the 

 Howers of each one of the shrubs ; besides those I observed two 

 shrubs standing solitarj' in private gardens. As the chief difference 

 between the flowers I found that one part had well developed stigmas 

 and smaller anthers which did not open, but fell off still closed with 

 the fading corolla, while others had a rudimentary stigma, though 

 the ovary and the style seemed to be normal, and larger anthers 

 shedding pollen freely; occasionally, however, I found among the 

 first kind of flowers a few anthers which opened and discharged 

 their pollen. Only four plants of all those observed belonged ta 

 the second kind and these four plants, as I found in comparing 

 again my notes with the plants, when the fruits were ripening, bore 

 not a single fruit, though all other shrubs surrounding them were 

 loaded with fruits. i'he three solitary plants, which all belonged to 

 the first kind, had only a few fruits; a smaU part of the flowers 

 apparently had been fertilized by the occasionally appearing fer- 

 tile anthers ; the number of fruiting panicles in these plants was 

 comparatively small and each panicle bore only i to 3, rarely more 

 fruits, while the shrubs in the group mentioned above, which were 

 growing side by side with pollen-bearing plants, had a very large 



