Vol. 45 TORREYA March 1945 



An Abnormal Balsam Fir 



David B. Cook 



Unusual growth forms of trees are of interest to the cytologist and the 

 geneticist as well as to the general botanist. Some atypical forms have com- 

 mercial or horticultural value, others are mere curiosities. Among the Pinaceae, 

 variations are usually minor and mostly concern twig placement and foliage 

 color. 



W. H. Bennett has reported (Quarterly Journal of Forestry, 30 (1) : 

 133-134. 1936) on a Norway spruce which, for four seasons after planting, 

 produced normal lateral branches; then, for the succeeding six years (up to 

 the date of writing) grew a single, branchless, upright stem. No explanation 

 for the phenomenon is suggested. 



During a recent field trip, my associate, Mr. Stacy B. Robeson of Platts- 

 burg, N. Y., showed me an unusual specimen of balsam fir (Abies balsamea 

 (L.) Mill.) on Valcour Island in Lake Champlain. The tree is growing at the 

 east edge of a woods of white spruce, white cedar and fir, on thin soil under- 

 laid by limestone. This specimen is abnormal in that there is no indication 

 that lateral buds have ever been produced. As a result, the tree is entirely de- 

 void of branches. At the end of the 1944 growing season, the total height of 

 this single, branchless stem was 85 inches. The diameter just above the ground 

 was 0.54 inches ; at the base of the 1944 internode, 0.32 inches. The nodes are 

 marked by distinct ridges in the bark and by a frill of needles, when present. 

 They indicate a total age of 20 years. The longest internode (1939) is 8.5 

 inches, that of the 1944 season 5.6 inches. The 1936 internode is the oldest 

 one still bearing needles. The distribution of foliage is the same as that on 

 normal leaders. Needles are of normal length but strongly keeled and with a 

 pointed tip. The terminal bud is bluntly conical and as big as the end of the 

 leader. 



Considering the small amount of foliage, height growth is good. But di- 

 ameter growth is deficient and the stem is so slender that it does not stand erect, 

 as will be seen in the accompanying figure. 



New York State Conservation Deppartment 

 Albany, New York 



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