384 HARPER: FACTORS INFLUENCING DISTRIBUTION 
not seem to have been properly published until it was taken up by 
Professor Sargent. Synonyms for these two species which are 
purely horticultural or of doubtful application are here omitted. 
The principal objection to the recognition of the latter species 
as distinct seems to have been its supposed intergradation with 
T. distichum. Elliott,* writing afew years after Nuttall, says of Z. 
imbricarium: ‘This is a small tree growing in pine-barren ponds. 
It produces its knobs (exostoses) more abundantly than the large 
variety ; and on its lower branches the leaves are frequently imbri- 
cated after the manner of the junipers. But on the upper branches 
the leaves are often expanded and distichous. It is perhaps only 
a stunted variety, growing in an unfavorable soil.’’ 
Seventy-two years later Professor Sargent+ remarks: “ No one 
unfamiliar with the fact that branches of the two forms occasion- 
ally appear on the same individual would imagine that the cypress 
trees with erect or pendulous thread-like branches and closely 
appressed acerose leaves belong to the same species as those with 
Spreading distichous branches and flat leaves.” 
Dr. Mohr’s observations on Taxodium in his “ Plant Life of 
Alabama ’’t are of interest as being among the latest published. On 
page 117,in speaking of the mesophile and paludial forests of 
‘the lower division of the coast pine belt, he says: ‘“ Groves of the 
pond or upland cypress just mentioned—a variety closely CoP” 
nected with the type by intermediate forms—cover the shallow 
pine-barren ponds and semi swampy woods of a poor, sandy ie : 
destitute of vegetable mold. This form of the cypress in the size 
and quality of its wood is greatly inferior to the typical cypress 
of the alluvial swamps, and is at once recognized by the leaves; 
which are closely appressed to the deciduous annual shoots. BF 
this peculiarity of the foliage a check to excessive transpiration !° 
provided during the time of drought, when the sandy soil is laid 
bare to the sun and its supply of water is failing.” 
On page 325 he says of the same plant; ‘‘ Of smaller size than 
the species, with the leaves reduced in size and closely ee ly 
: : : jkin 
to the deciduous branchlets, thus imparting to the tree a exes 
* Bot. S.C. & Ga. 2: 643. 1824. 
Tt Sylva N. A. 10: 152, 1896. 
¢ Contr. U. S. Nat. Herb, 6: 1901. 
