178 The Trees of Great Britain and Ireland 



analogous to the cone-shaped base of the former ; and from Coulter's observations 

 it would appear that seedlings of Taxodium are also rare here, and that it is 

 being beaten in the struggle by the Nyssa, the seedlings of which are very 

 abundant. 



A disease' due to a fungus has attacked many of the trees in the Mississippi 

 valley ; the heartwood is found when the trees are cut down to be full of holes 

 1^ to f inch in diameter. 



Taxodium is one of the most striking and characteristic trees in the Gulf States, 

 having its branches often covered with Tillandsia usneoides, the " Spanish moss " 

 of the inhabitants, the long grey masses of which wave in the wind and give it 

 a strange appearance. The trunk takes many curious forms, which seem to be 

 induced by the nature of the soil and the depth of the water, sometimes branching 

 low and surrounded by buttresses, sometimes growing straight up to a considerable 

 height (Plates 52-53).^ From the stout wide-spreading roots arise woody cylindrical 

 projections, sometimes above a foot in diameter and 5 to 7 feet high, which are 

 called " cypress knees." The growth and functions of these have been the source of 

 much discussion.^ Berkeley^ supposed that they serve to aerate the submerged 

 roots ; others have thought that they help to anchor the roots in soft muddy soil. 

 As the knees, however, occur to some extent even on ground which is never flooded, 

 as in the trees at Syon, these suppositions, though highly probable, must remain 

 somewhat doubtful. 



The knees are hollow inside, and smooth externally, being covered with a reddish, 

 soft, and spongy bark. They never show any sign of vegetation, and will not put 

 forth shoots, even if wounded and covered with earth. 



Cultivation 



In England the Taxodium grows much better than might be expected consider- 

 ing how much colder and shorter are our summers than those of its native country. 

 It was introduced by John Tradescant about 1640', and described by Parkinson* as 

 Cupressus americana. 



For some unexplained reason it has lost the popularity it once enjoyed, and is 

 now seldom planted, though it grows well in the southern and western counties. I 

 have raised it from American seed, which, however, must be soaked in warm water 

 for some time, and placed in a warm house to get good results. It grows rapidly at 

 first, but as the young wood is not ripened, and no terminal bud formed (which 



' Coulter, Missouri Bot. Garden Report, 1 899, p. 23. 



' For the negatives of the first of these photographs I am indebted to Miss E. Cummings of Brookline, Mass., a lady 

 who is second to none in her lofe of and knowledge of trees. The second, which was sent by Mr. W. Ashe, represents a 

 typical cypress swamp on the Roanoak river, North Carolina, which has never been cut for timber. 



3 Sargent, he. cii. 152, note i ; Coulter, loc. cit. The best review I know of the literature on this subject is in a letter 

 by R. H. Lambom in Garden and Forest, iii. p. 21, which should be consulted by those interested, and which is illustrated by 

 a very curious photograph, taken at Lake Monroe in Central Florida, of the denuded roots of the tree, showing that in some 

 cases, at least, the anchor theory is proved. 



Card. Chron. 1857, p. 549. 



' Parkinson, Theatr. 1477, fig. In Catalogue of Trees, London, 1730, p. 25, it is stated that the first tree, raised 

 in Tradescant's garden near Lambeth, was then still living, being 40 feet high by 2 fathoms in girth. 



