NOTES ON THE BALD CYPRESS. 



Every fact that serves to show a rehition between the circumstances 

 that surround an animal or plant and its peculiarities of structure has 

 a certain importance to naturalists. It may aid in the solution of the 

 great problems they now have in hand. I therefore venture to make a 

 record of certain facts concerning the habits of the swamp cypress (Tax- 

 odium dlstichium) of our Southern States which seem to me to be impor- 

 tant. The observations have been made at various times during the last 

 ten years, but principally in connection with the work of the Kentucky 

 Geological Survey, in the district west of the Cumberland river. 



It requires but little attention to this species to make it plain that it is 

 subject to great clianges of conditions, arising from the peculiar character 

 of the soil in which it lives. The condition of the low lands where it 

 finds its station may bring it into any one of several widely divergent 

 conditions of soil, with very slight variations of position. I wish to trace 

 the effects of these changes of condition upon the peculiar projections 

 from the roots, which are commonly known as knees. These excrescences 

 of the roots have received so little attention from naturalists that it will 

 be necessary to premise an account of their variations by some statement 

 concerning their nature. 



Along the main roots of the Taxodium, as it exists in the swamps, we 

 have a series of projections which at first appear as slight tuberosities on 

 the upper side of the root. These projections are formed somewhat ir- 

 regularly, but they frequently occur at intervals of no more than two or 

 three inches along the crest of the root. The result of these frequent 

 excrescences is that the root is vertically flattened, presenting in trans- 

 verse section an elliptical shape, the vertical axis being double or ti-eble 

 the length of the horizontal axis. Certain of these tubercles grow more 

 rapidly than the others, and present a curiously dentate appearance; so 

 that the root, seen transverse to the length, reminds one of the jaw of 

 a saurian reptile. This likeness is enhanced by the fact that the pro- 

 jections are at first sharply conical and slightly bent back towards the 

 main stem of the tree. The young knees grow very rapidly until they lift 



