168 
counties in the State have been worked with such persistence and with such 
painstaking accuracy. Others of the species are doubtless restricted to the 
rich alluvial soils of the lower Wabash Valley. 
To these might be added a small group showing a distribution so 
unconnected as to be extremely difficult of explanation. An jnstance’ is 
found in Pinus Strobus 1L., which is found in Lake, Porter and Laporte, 
extreme northwestern counties; Warren and Montgomery, western-central 
counties; and in Clark in the southeastern part of the State. Its occur- 
rence in the northwestern counties affords no difficulty; the western- 
central location might be explained as a continuation of the former area; 
but the recurrence of the species in Clark County on the Ohio River in the 
eastern part of the State furnishes a difficult problem. In the case, also, of 
Crategus coccinea I.., we find equally unrelated areas, this species being 
reported only from Noble and Steuben, extreme northeastern counties, and 
Floyd, a southern county on the Ohio River. The genus Cratzegus, how- 
ever, presents such difficulties in the discrimination of species that the case 
just cited may possibly be due to lack of accuracy in determination. 
The species limited to Knox, Gibson and Posey counties or to some 
part of the area are as follows: 
Taxrodium distichum (1.) lL. C. Richards. 
Hicoria Pecan (Marshall) Britton. 
Quercus lyrata Walter. 
Quercus Michaurii Nuttall. 
Quercus falcata Michaux. 
Celtis mississippicnsis Bose. 
Crategus viridis Linnwus. 
Crataegus nitida (Engelmann) Sargent. 
Gleditsia aquatica Marshall. 
Ilex decidua Walter. 
Forestiera acuminata (Michaux) VPoinet. 
In addition to these species, which seem strictly limited to the region 
hamed, two others have been reported from a single additional county : 
Catalpa speciosa Warder. Gibson, Knox, Posey and Vigo. 
Pravinus Michauwrii Britton. Gibson, Posey and Marion. 
The Bald cypress (Taxodium) is a southern swamp form, which finds 
in the Indiana locations its extreme northeastern limits. In Indiana it is 
