Harper : Observations on Taxodium 107 



sil cypress stumps have been found on the shores of Chesapeake 

 Bay with their roots imbedded in Cretaceous strata. It was at 

 first supposed that the stumps themselves were of Cretaceous age, 

 but subsequent investigations by the same author and Dr. Hollick 

 have shown that the trees grew in Pleistocene times, sending their 

 roots down into the Cretaceous strata on which they stood, and 

 the stumps have been preserved /// situ. 



The actual contact of T. imhricarmm with the Lafayette for- 

 mation (or what passes for it) has not yet been observed, and 

 could hardly be without having special excavations made for the 

 purpose, but I have often seen this formation exposed (particularly 

 in railroad cuts) within a few yards of colonies of this tree. 



The relations of the two species under consideration to the 

 geological formations are well illustrated at Bull Head Bluff on 

 the Satilla River in Camden County, Georgia, which I visited in 

 August, 1902. The bluff is about eight feet high, and exhibits 

 the following section, in descending order : Two feet of Colum- 

 bia sand, five feet of reddish clay (Lafayette ?), and about a foot 

 of stiff bluish clay (doubtless Tertiary, but exact age unknown). 

 Typical Taxodiiun distichum grows here along the water's edge, 

 below the Lafayette, while a hundred yards or so away from the 

 river equally typical 7! imbricarhim flourishes in moist pine-bar- 

 rens. 



Ecologlsts have had a good deal to say recently about drained 

 and undrained swamps, and the remarkable differences in their 

 flora. If they would examine the habitats of the two taxodiums 

 they would find that T. distichum always grows in "drained" 

 swamps, and T. imbricaritim usually in ponds, which are of course 

 " undrained." In the Southeastern States, as in other parts of 

 the country, there are very few species common to both habitats. 

 In their relation to limestone the taxodiums are equally distinct, 

 T. distichum being essentially a limestone-loving species and T. 

 imbricari7im]Ms\. the opposite. (The latter often, perhaps always, 

 grows over hmestone, but never in contact with it, some more 

 recent formation always intervening.) 



There are also some additional morphological characters which 

 I overlooked before, by which the two species under consideration 

 may be distinguished. In Washington in the spring of 1902 my 



