i Wee 
which (. witida came into the State. There is as much reason for regard- 
ing the Illinois station as the westward extension of the Indiana station as 
the reverse. 
The Water Locust or Thorn Tree (Gleditsia aquatica Marshall) is 
found in a few localities in Gibson, Knox and Posey counties in sloughs and 
cypress swamps. This is a northern and eastern extension of a definitely 
southern species which must have entered our flora at a time when the 
swamp areas of the river bottoms were practically continuous and which 
has been able to maintain itself only in occasional deep river Swamps 
within our boundaries. In Indiana the species is both rare and local and 
one which will, in all probability, soon disappear. 
One of the Hollies (/ler decidua Walter) occurs occasionally in the 
three southwestern counties, being invariably restricted to the borders of 
ponds and sloughs near water courses. Although at times it forms fairly 
dense thickets, it rarely, in our region, reaches tree size. The distribution 
as given in Sargent’s “Trees of North America,” p. 618, is significant in 
this connection: “Borders of streams and swamps in low moist soil; 
southern Virginia to western Florida in the region between the eastern base 
of the Appalachian Mountains and the neighborhood of the coast, and 
through the Gulf States to the valley of the Colorado River, Texas, and 
through Arkansas and Missouri to southern Illinois: usually shrubby east 
of the Mississippi River and only arborescent in Missouri, southern Arkan- 
sas and eastern Texas.” It is merely another instance in which an essen- 
tially coastal form has found its way deep into the interior. When con- 
sidered in connection with other cases, some of which have been cited, the 
conclusion is almost inevitable—that the only adequate explanation is to 
be found in relating it to the northward stretching arm of the Gulf of 
Mexico. 
Pond-bush (Forestiera acuminata (Michaux) Poiret) is another spe- 
cies strictly limited to Gibson, Knox and Posey counties where “it is found 
in swamps, on the borders of ponds and on low river banks. If is very 
tolerant of shade and is frequently found growing in a thick stand of tall 
trees.’ The Indiana stations represent the extreme northeastern limit of 
this species, which extends westward to Missouri and south to Texas. In 
Indiana it is ordinarily a shrub, at times forming almost impenetra- 
ble thickets. It is impossible to determine from the data at hand as 
to whether this is a western or southern form. In either case its habitat, 
7Deam. Op. Cit. 342. 
