58 MISSOURI BOTANICAL GARDEN. 
water upon the ground and the diameter of the base at the 
water’s edge was twelve feet. The same tree was observed 
in the fall when the ground was dry, and its circumference 
where the roots entered the ground was 45 feet. The 
tupelo in the lower figure of Plate 19, measured 55 feet in 
circumference where the roots entered the ground, and its 
height was only 45 feet, a considerable portion of the up- 
per part having been broken off. What the advantage 
accruing to the tupelo from this enlarged base may be is a 
matter of much speculation; none of the suggestions so far 
offered have seemed adequate to the writer. It is certain 
at least, that no physiological cause has yet been assigned. 
Where the water supply is scanty, the base is only slightly 
enlarged, and under ordinary conditions the trunk is normal. 
The Cypress thrives well in similar areas in this region, but 
in the Kennett district, nearly all the trees are tupelos. 
The cypresses are old, dying or dead, and few younger ones 
are coming on to replace them. In such places one notes 
particularly the great abundance of epiphytic vegetation. 
Every dying tree, stump, cypress knee, decaying log or 
floating limb is literally hidden by a rank growth of grasses, 
sedges, Rosa Carolina, Itea Virginica and many other forms. 
(Plate 20.) As the tupelo base enlarges, it affords a favor- 
able foothold for the epiphytic fern, Polypodium incanum, 
which often completely covers it. This fern possesses the 
characteristic of shriveling and rolling up its coriaceous 
leaves during dry weather, and quickly spreading them out 
again, and becoming bright green in rainy weather. 
Taxodium distichum. 
The habitat of the cypress is quite similar to that of the 
tupelo; though it seems probable that the cypress is not 
the equal of the tupelo in the struggle for the occupancy 
of this territory. The seedlings and young growing trees 
of the latter are much more numerous than those of the 
