June 1900.] BOTANICAL SOCIETY OF EDINBURGH 315 



18 inches in circumference. The branch formed an angle 

 of 90 degrees with the axis, and then bent gently upwards 

 through 8 inches to the vertical. It showed a clear 

 unbranched handle 9 inches long and 7 inches in girth, 

 increasing to 7| inches, when it forked into two branches, 

 one on the east, the other on the west side. The east 

 branch, forming about half the broom, was dead ; the west 

 half was in vigorous growth. 



A special feature of the broom was the remarkable 

 development of long shoots, far in excess of the number 

 usually formed on the normal branches. Other characters 

 were the marked negative geotropism of these shoots, the 

 decay of their apices in the autumn, and lastly, the excessive 

 development of dormant buds. These features, in con- 

 junction with the numerous long needles on the long 

 shoots, gave the broom a particularly well clad appearance. 



The broom-bearing Picea has not been planted out, 

 but allowed to remain in the nursery, on account of its re- 

 markable malformation. The tree (Plate II.) is a little over 

 six feet in height, and is fourteen years old. The broom, 

 which originates three feet from the ground, apparently 

 began to develop when the tree was in its eighth year. 

 Since then, it has absorbed the larger part of the supplies, 

 dwarfing tlie growth of the parts above. Below it, the 

 axis has a girth of 6^ inches, while immediately 

 above it is disproportionately small. The broom extends 

 quite around the main stem, and has a circumference of 

 5 feet. Its shoots are hypertrophied to a marked extent, 

 there being an excessive development of bark, the outer 

 layers of which are of a fine, dark red colour. Dormant 

 buds have developed so copiously that the lateral shoots 

 stand in close set rows, mutually compressing each other 

 laterally, while the leaves developing on the innermost 

 twigs are contorted and etiolated. 



This crowding together of branches gives the broom 

 such a dense character that pieces have to be hewn out 

 in order that one may get at the details of structure and 

 origin. Another result of the mutual pressure of the 

 branches is the masking of the negative geotropism, so 

 usual a character in brooms. The shoots do show to 

 some extent this character however, inasmuch as they 



