TRKl'iS (IROWINC; NKAR \VA Tl'K. 



KM 



the soil.' This opinion fnids c-onfirniation in the fact that 

 scarcely any other tree of our forests offers a j;realer resistance 

 to the force of storms under the most unfav()ural)le soil con- 

 ditions. 



*' On the other hand it is held that the function of the knees is 

 principally physiological by acting as organs of aerii^tion. The 

 exposed parts of the knees effect the absorption, and by their 

 chlorophyll-bearing tissue, the partial decomi)osilion of atmos- 

 pheric gases under the influence of light, and their trans- 

 mission to the sap of the roots, promote the process of 

 assimilation in parts of the tree debarred from a sufficient 

 supply of the same. 



"With the decay of the tree, the knees rot and finally disap- 

 pear ; the same is said to take place after the drainage of the 

 swamp. Not being needed they are not present in the trees 

 grown on high land. 



" From the fact that the knees serve the tree mechanically 

 by increasing the force of the tree to maintain its foothold in 

 a yielding ground and that further by their physiological 

 function the processes involved in its nutrition and growth 

 are promoted, it appears clearly that in the peculiar develop- 

 ment of the root system the cypress possesses the means of 

 adapting itself perfectly to the conditions of its immediate 

 surroundings." 



SOUTHERN WHITE CEDAR. {Plate XLV.) 



Chamcccyparis thyoldes. 



FAMILY SHAPE HEIGHT RANGE TIME OF BLOOM 



Pine. Spire-like; brancheSy 30-90 yVi-^. Atlantic seaboard and April, May, 

 horizontal. Gulf states to Miss. 



Bark : light reddish brown ; very fil)rous ; se])arating into loose scales. 

 BrancliUts: brown, their thin bark also separating. Leaves: tiny ; simple ; 

 ovate and awl-sliaped ; overlapping each other like scales and growing closely 

 together in rows of four, np and down the branchlets. Dull brownish or blue- 

 green ; glaucous. Cones : \\7s.\(S\'^ one-half an inch wide; globose; sessile on 

 leafy branches ; purplish at maturity ; glaucous, and ojiening towards the centre 

 when ripe, not towards the base. Scales : thick ; several-pointed and as though 



