1921-22.] BOTANICAL SOCIETY OF EDINBURGH 117 



Mainland, 1st October 1921, H. H. Johnston. Native. 

 Common. Plants wholly submerged in water. A new 

 record for this variety for H. C. Watson's count}^ No. Ill 

 Orkney. 



Note on Juvenile Characters in Root and Stem 

 Cuttings of Acanthus montanus. By L. B. 

 Stewart. 



(Read 18th May 1922.) 



Taking a root of Acanthus about a foot long, dividing 

 it into portions of from 3 to 4 inches, and placing these in 

 a propagating case, it is found that the portion with the 

 root apex attached continues to elongate, while the other 

 portions generally develop side roots near the basal ends. 

 In root cuttings of Acanthus there is always a tendency 

 on the pai't of the cutting to produce more roots to begin 

 with than there is for shoot production. On the meriste- 

 matic tissue at the upper ends of each portion buds are 

 formed of which one or two produce growth shoots, the 

 remaining buds lying dormant. Seldom are more than 

 two growth shoots sent up. Should three or four growths 

 start away they have very short internodes and are weak 

 in growth. The dormant buds remain fresh and green for 

 two or three years and are ultimately overgrown by the 

 growth shoots. Should, however, the growth shoots be 

 knocked off or be cut off, one or more of the dormant buds 

 will produce growth shoots. 



The appearance of the growth developed from the 

 three portions of root show marked contrasts. The shoot 

 developed from the youngest piece of root which bears the 

 root apex is juvenile in character whereas the growth 

 formed on the oldest portion shows much more adult 

 characters. 



Bud formation on the normally lower end of the root 

 portion is more difficult to induce, but this can be 

 accomplished by inserting the portion of root first in the 

 normal position until callus has formed, then by inverting 

 the cutting and at the same time giving the callus a wound 

 stimulus, buds are thereafter formed. Buds formed on the 



