DUPLICATION AND COHESION IN THE MAIN AXIS 
IN CICHORIUM INTYBUS 
AVeD. SLOuUr 
New York Botanical Garden 
The terms duplication and cohesion may be used to designate a 
very special type of fasciation which the writer has observed in the 
variety of chicory cultivated under the name ‘‘red-leaved Treviso.” 
The most distinctive characteristic of this type of fasciation is the 
duplex nature of the main axis. From a single root a double 
stem arises with the two parts, as a rule, strongly united. The 
duplex nature is indicated by a pair of grooves which extend in the 
direction of the long axis and round out the two stem-elements. This 
is quite well shown in number 5 of the accompanying plate XII. 
This type of fasciation differs from the banded and cone types 
most usually seen in that here two stem-elements of equal size and 
rank are clearly in evidence throughout a segment of unequal 
diameters, giving a symmetry that is bilateral. Also the fasciation 
is confined to the middle and lower portions of the stem and decreases 
upwards, the main axis often becoming at its apex quite symmetri- 
cally simplex. 
I have been unable to find in the literature any reference definitely 
mentioning fasciation of this particular type. It appears not to have 
been noted and described even in this rather well-known variety of 
chicory. 
In the degree and the extent of the duplication there is much 
variation. The most extreme condition of duplication is seen in the 
complete separation of the two stem-elements with each perfectly 
formed and without lesions, as is shown in no. 7 of Plate XII. In many 
cases the two elements are indicated only by grooves which extend 
from close to the base of the plant to a height of about three feet. 
The length of the grooves and the corresponding segment of evident 
duplication may, however, be reduced to mere traces, as is shown in 
no. 3 at a or in no. 4 from a to 8, as indicated. In a few plants of 
this strain there is no evidence of duplication and the phyllotaxy is 
of a single and regular spiral only. 
Each stem-element has its own phyllotaxy in so far as this can be 
expressed. In the most pronounced duplex condition there are clearly 
two separate spirals in evidence. The phyllotaxy of one is not a’ 
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