RARE FORMS OF FERNS —VIII. 



An Abnormal Cinnamon Fern. 



It was once thought, on this side of the water, that 

 there must be something peculiar to the soil or climate 

 - of Great Britain that would account for the great varia- 

 tion in its fern species, but the longer we study our 

 own ferns, the more certain it appears that fern varia- 

 tion in the old world is not so much a matter of soil 

 and climate as it is of careful observation and search 

 on the part of fern students themselves. Within a 

 comparatively short time several variations from nor- 

 mal Osmund a plants have been recorded from America 

 and it is quite likely that others will be noted in the 

 future. In fact, to this lengthening list must now be 

 added the form illustrated in the accompanying cut 

 which was drawn from a frond collected by A. S. Bos- 

 sart in a bog near Burton, Geauga Co. Ohio, in the 

 early part of the summer of 1907. 



A glance at the illustration will show that the new 

 form is characterized by pinnae that are devoid of pin- 

 nules for some distance toward their tips leaving the 

 slender mid-ribs as stalks supporting the apical cluster 

 of pinnules. In a large number of pinnules toward the 

 base of the frond a tendency is shown to repeat the 

 outline of the pinnae, but a careful examination of the 

 frond, itself, shows the terminal structures to be not 

 mere expansions of green tissue but those more re- 

 markable structures known as ascidia or pitchers. 

 Ascidia are known on a great variety of flowering 

 plants in some being the normal condition as in the 

 pitcher-plants. In others, as in clover-leaves which 

 sometimes assume this form, they are clearly abnormal. 

 Some few ferns are known which normally form as- 



107 



