24 BULLETIN 272 ; U. S. DEPARTMENT OF AGRICULTURE. 



sometimes remarkably wide, buttressed or ridged base. Toward 

 maturity this form at the base gradually disappears as a result of 

 change in growth toward a cylindrical or columnar form. Another 

 cause is geological in character. The remaining basal swell becomes 

 buried during the course of several centuries by alluvial and peaty 

 deposits, often to a depth of from 3 to 5 feet. In swamps not sub- 

 ject to high floods cypress usually has only slight basal swell (fig. 4). 

 The narrowly pyramidal and symmetrical crown of smaller branches 

 during earlier life gives way gradually during the second and third 

 centuries to a broad, flat-topped crown consisting of a few wide- 

 spreading, heavy limbs. This form persists during from two to four 

 centuries; then decay, accompanied by winds, usually carries away 

 considerable of the original top (PL III). In the open, cypress 

 maintains a full crown of many small branches more cylindrical in 

 form and very much less dense than the eastern red cedar. 



BARK. 



The bark shows extreme variation from a thick, deeply furrowed 

 fibrous bark to a thin scaly one. The tree is very responsive to 

 physical environment. In Florida, for example, near fresh, deep 

 water, the bark at all ages is very thin, soft-fibered, and light brown 

 in color, while in adjacent situations with sluggish or stagnant water 

 the bark is thick and of a reddish color, the heartwood is darker and 

 somewhat heavier, and the sapwood thinner and more uniform in 

 width (PL X). In the great Wilmington Swamp of North Carolina 

 the bark is prevailingly thick and firm. During logging it breaks 

 apart into long, stringy fibers of a rich brownish-red color. • The 

 difference in bark thickness ranges mostly from \ to 1^ inches. All 

 intermediate gradations are present, and when the two extremes 

 appear in the same region they are accompanied by different condi- 

 tions of soil and moisture. 



The foliage consists of very small flat or needle-shaped leaves, 

 arranged either in two ranks or closely appressed to fragile branchlets. 

 Cypress is a conifer, but not an evergreen tree, and both leaves and 

 branchlets are dropped in the fall. The wide variation in leaf form 

 appears to be accompanied by corresponding differences in the 

 amount and acidity of the water supply. 



BOOT SYSTEM. 



The conical base of cypress divides below the surface into about 

 six to ten strong descending and spreading roots, which provide a 

 deep anchorage for the tree. The form suggests that of a mush- 

 room anchor. In addition to the descending roots, a number of 

 large laterals extend outward near the surface like cables and form 



