( 135 ) 



The most interesting feature of the Bald Cypress is the develop- 

 ment of the so-called cypress "knees." In situations where the 

 roots of these trees are permanently or periodically under water, 

 soft woody growths up to ten feet in height found on the sub- 

 merged roots project above the surface of the water. These 

 growths later become hollow. There has long been a question con- 

 cerning the function of these "knees." It is generally believed 

 that the}- assist in supplying atmospheric oxygen to the submerged 

 roots. This explanation is based on the observations that these 

 growths form only when the roots are submerged, that their size 

 depends on the depth of the water and that if they too become 

 covered with water the trees die. On the other hand it has been 

 maintained that the hardened surface of these knees could not 

 absorb oxygen, and that if such were the case nature would provide 

 a broader rather than a narrowing surface of limited area for 

 absorption. Root anchorage has seemed the function from this 

 viewpoint. They serve no reproductive purpose, for they have no 

 buds and die when a tree is cut. 



The fact remains, however, that among trees adapted for 

 swamp growth, Bald Cypress is the only one that thrives in soil 

 continuously flooded. Fifty or a hundred of these knees may sur- 

 round the base of the tree, extending some distance from the 

 trunk. In addition to the "knees," the base of the tree generally 

 has large flutes or buttresses in wet situations. Mature trees are 

 usually hollow at the base. 



The wood of the Bald Cypress is very durable, as might be 

 expected, and has been much advertised as the "Wood Eternal." 

 Under wet conditions the trees may attain enormous diameters, 

 whose proportion to their heights may exceed that exhibited by 

 the gigantic Sequoias of California. 



Furthermore, the Bald Cypress displays an anomaly among coni- 

 fers by sending up vigorous sprouts from cut stumps. This depar- 

 ture, as has already been noted, is exhibited in the Pitch Pine and 

 Redwood. 



General Discussion 



There are only two or three kinds of Bald Cypress, the number 

 depending, as in all such cases, on the definition of a species. 



